Bone graft delivery system

ABSTRACT

The present invention relates to an apparatus and method for near-simultaneous and integrated delivery of bone graft material during the placement of surgical cages or other medical implants in a patient&#39;s spine. The integrated fusion cage and graft delivery device according to various embodiments delivers and disperses biologic material through a fusion cage to a disc space and, without withdrawal from the surgical site, may selectably detach the fusion cage for deposit to the same disc space. The integrated fusion cage and graft delivery device is formed such that a hollow tube and plunger selectively and controllably place bone graft material and a fusion cage in or adjacent to the bone graft receiving area.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 13/714,971, filed Dec. 14, 2012, which is acontinuation-in-part of U.S. patent application Ser. No. 13/367,295,filed Feb. 6, 2012, which is a continuation-in-part of U.S. patentapplication Ser. No. 12/886,452, filed Sep. 20, 2010, which claims thebenefit of U.S. Provisional Application No. 61/243,664, filed on Sep.18, 2009, and cross-references U.S. Provisional Application No.61/439,712, filed Feb. 4, 2011, PCT Application No. IA PCT/US11/52278,filed Sep. 20, 2011, PCT Application No. IA PCT/US13/23992, filed Jan.31, 2013, and U.S. Design patent application No. 29/453,829, filed May3, 2013, the entire disclosures of which are hereby incorporated hereinby reference in their entirety.

FIELD OF THE INVENTION

This disclosure relates to orthopedic surgery, and more specifically toan apparatus and method for near-simultaneous and integrated delivery ofbone graft material during the placement of surgical cages or othermedical implants in a patient's spine.

BACKGROUND OF THE INVENTION

According to the American Academy of Orthopedic Surgeons, about 250,000spinal fusion surgeries are performed every year, mostly on adultsbetween the ages of 45 to 64. Spinal fusion is a process by which two ormore of the vertebrae that make up the spinal column are fused togetherwith bone grafts and internal devices (such as rods) that heal into asingle solid bone. Spinal fusion can eliminate unnatural motion betweenthe vertebrae and, in turn, reduce pressure on nerve endings. Inaddition, spinal fusion can be used to treat, for example, injuries tospinal vertebrae caused by trauma; protrusion and degeneration of thecushioning disc between vertebrae (sometimes called slipped disc orherniated disc); abnormal curvatures (such as scoliosis or kyphosis);and weak or unstable spine caused by infections or tumors.

Individuals who suffer degenerative disc disease, natural spinedeformations, a herniated disc, spine injuries or other spine disordersmay require surgery on the affected region to relieve the individualfrom pain and prevent further injury to the spine and nerves. Spinalsurgery may involve removal of damaged joint tissue, insertion of atissue implant and/or fixation of two or more adjacent vertebral bodies.In some instances a medical implant is also inserted, such as a fusioncage. The surgical procedure will vary depending on the nature andextent of the injury. Generally, there are five main types of lumbarfusion, including: posterior lumbar fusion (“PLF”), posterior lumbarinterbody fusion (“PLIF”), anterior lumbar interbody fusion (“ALIF”),circumferential 360 fusion, and transforaminal lumbar interbody fusion(“TLIF”). More recently, direct lateral interbody fusion (“D-LIF”) hasbecome available. A posterior approach is one that accesses the surgicalsite from the patient's back, an anterior approach is one that accessesthe surgical site from the patient's front or chest, and a directlateral approach is on that accesses the surgical site from thepatient's side. There are similar approaches for fusion in the interbodyor cervical spine regions. For a general background on some of theseprocedures and the tools and apparatus used in certain procedures, seeU.S. Prov. Pat. Appl. No. 61/120,260 filed on Dec. 5, 2008, the entiredisclosure of which is incorporated by reference in its entirety. Inaddition, further background on procedures and tools and apparatus usedin spinal procedures is found in U.S. patent application Ser. No.12/632,720 filed on Dec. 7, 2009, the entire disclosure of which isincorporated by reference in its entirety.

Vertebrectomy, or the removal or excision of a vertebra, is another typeof spinal surgery that may be necessary to alleviate pain and/or correctspinal defects, such as when disk material above and below a particularvertebra protrudes from the spine and contacts the spinal cord. Once theproblematic vertebra is removed, a specialized fusion cage (also calleda vertebrectomy cage) may be inserted into its place to restorestructural continuity to the spine.

Some disadvantages of traditional methods of spinal surgery include, forexample, the pain associated with the procedure, the length of theprocedure, the complexity of implements used to carry out the procedure,the prolonged hospitalization required to manage pain, the risk ofinfection due to the invasive nature of the procedure, and the possiblerequirement of a second procedure to harvest autograft bone from theiliac crest or other suitable site on the patient for generating therequired quantity of cancellous and/or cortical bone.

A variety of semisolid bone graft materials are available on the marketwhich ostensibly increase spinal fusion rates without the morbidity ofautograft bone harvest. Each of the manufacturers espouses their productas the most advantageous for healing. These products all have similarhandling characteristics and the literature reveals that they havesimilar healing prospects. They come in a syringe and it is up to thesurgeon to apply the selected material to the target site. The mostcommon site for application is to the disk space after it has beenprepared to a bleeding bed and ready to accept a cage and/or thegrafting material. This represents a long and narrow channel even inopen procedures. The surgeon is left to his own devices as to how to getthe graft from its container to the active site. The devices which havebeen used have included a “caulking gun” construct and a variety ofbarrel shaft with a plunger design.

Bone graft typically includes crushed bone (cancellous and cortical), ora combination of these (and/or other natural materials), and may furthercomprise synthetic biocompatible materials. Bone graft of this type isintended to stimulate growth of healthy bone. As used herein, “bonegraft” shall mean materials made up entirely of natural materials,entirely of synthetic biocompatible materials, or any combination ofthese materials. Bone graft often is provided by the supplier in a gelor slurry form, as opposed to a dry or granule form. Many companiesprovide various forms of bone graft in varying degrees of liquidity andviscosity, which may cause problems in certain prior art deliverydevices in both prepackaged or packaged by the surgeon embodiments. Inaddition, the method of delivery of bone graft to a particular locationvaries depending on the form of the bone graft utilized.

Autogenous bone (bone from the patient) or allograft bone (bone fromanother individual) are the most commonly used materials to induce boneformation. Generally, small pieces of bone are placed into the spacebetween the vertebrae to be fused. Sometimes larger solid pieces of boneare used to provide immediate structural support. Autogenous bone isgenerally considered superior at promoting fusion. However, thisprocedure requires extra surgery to remove bone from another area of thepatient's body such as the pelvis or fibula. Thus, it has been reportedthat about 30 percent of patients have significant pain and tendernessat the graft harvest site, which may be prolonged, and in some casesoutlast the back pain the procedure intended to correct. Similarly,allograft bone and other bone graft substitutes, although eliminatingthe need for a second surgery, have drawbacks in that they have yet tobe proven as cost effective and efficacious substitutes for autogenousbone fusion.

An alternative to autogenous or allograft bone is the use of growthfactors that promote bone formation. For example, studies have shownthat the use of bone morphogenic proteins (“BMPs”) results in betteroverall fusion, less time in the operating room and, more importantly,fewer complications for patients because it eliminates the need for thesecond surgery. However, use of BMPs, although efficacious in promotingbone growth, can be prohibitively expensive.

Another alternative is the use of a genetically engineered version of anaturally occurring bone growth factor. This approach also haslimitations. Specifically, surgeons have expressed concerns thatgenetically engineered BMPs can dramatically speed the growth ofcancerous cells or cause non-cancerous cells to become more sinister.Another concern is unwanted bone creation. There is a chance that bonegenerated by genetically engineered BMPs could form over the delicatenerve endings in the spine or, worse, somewhere else in the body.

Regenerative medicine, which harnesses the ability of regenerativecells, e.g., stem cells (i.e., the unspecialized master cells of thebody) to renew themselves indefinitely and develop into maturespecialized cells, may be a means of circumventing the limitations ofthe prior-art techniques. Stem cells, i.e., both embryonic and adultstem cells, have been shown to possess the nascent capacity to becomemany, if not all, of the 200+ cell and tissue types of the body,including bone. Recently, adipose tissue has been shown to be a sourceof adult stem cells (See e.g. Zuk, Patricia Z. et al., “MultilineageCells from Human Adipose Tissue: Implication for Cell-Based Therapies,”Tissue Engineering, April 2001, 7:211-28; Zuk, Patricia A. et al.,“Human Adipose Tissue Is A Source Of Multipotent Stem Cells,” MolecularBiology of the Cell, 2002, 13:4279-4295). Adipose tissue (unlike marrow,skin, muscle, liver and brain) is comparably easy to harvest inrelatively large amounts with low morbidity (See e.g. Commons, G. W.,Halperin, B., and Chang, C. C. (2001) “Large-volume liposuction: areview of 631 consecutive cases over 12 years” Plast. Reconstr. Surg.108, 1753-63; Katz, B. E., Bruck, M. C. and Coleman, W. P. 3 (2001b)“The benefits of powered liposuction versus traditional liposuction: apaired comparison analysis” Dermatol. Surg. 27, 863-7). Accordingly,given the limitations of the prior art spinal fusion techniques, thereexists a need for a device that incorporates regenerative cells, e.g.,stem cells that posses the ability to induce bone formation.

Many different methods and approaches have been attempted to induce boneformation or to promote spinal fusion. The traditional devices forinserting bone graft impair the surgeon's visualization of the operativesite, which can lead to imprecise insertion of bone graft and possibleharm to the patient. The caulking gun and the collection of largebarrel/plunger designs typically present components at the top of theirstructure which block the view of the surgical site. The surgeon mustthen resort to applying pressure to the surgical site to approximate thelocation of the device's delivery area. Such rough maneuvering canresult in imprecise placement of bone graft, and in some cases, ruptureof the surgical area by penetrating the annulus and entering theabdominal cavity. Also, in some surgical procedures, the devices forinserting bone graft material are applied within a cannula inserted orplaced in the surgical area, further limiting the size and/or profile ofthe bone graft insertion device. When a cannula is involved, sometraditional devices such as the large barrel/plunger designs and/or thechalking gun designs simply cannot be used as they cannot be insertedwithin the cannula.

Traditional devices for inserting bone graft deliver the bone graftmaterial at the bottom of the delivery device along the device'slongitudinal axis. Such a delivery method causes the bone graftingmaterial to become impacted at the bottom of the delivery device, andpromotes risk of rupture of the surgical area by penetrating the annulusand entering the abdominal cavity. Further, traditional devices thatdeliver bone graft material along their longitudinal axis may causerupture of the surgical area or harm to the patient because of theensuing pressure imparted by the ejected bone graft material from thelongitudinal axis of the device.

As mentioned, the method of delivery of bone graft to a particularlocation varies depending on the form of the bone graft utilized. Forexample, in the case of slurry type bone graft, various dispensingdevices have been developed having applicators designed to accommodatethis type of bone graft. One such device is disclosed by U.S. Pat. No.5,925,051 issued to Mikhail on Jul. 20, 1999 (“Mikhail”). Mikhailprovides a caulking gun type dispenser for introducing bone graft in anenlarged bone (e.g. femoral) cavity. The device preferably includes abarrel pre-loaded with bone graft and a cannulated ejector positionedover a multi-section guide wire. This arrangement purports to accomplishboth ejecting bone graft from the barrel and compacting the bone graftmaterial while being guided on the guide wire. Mikhail, however, isdesigned solely for use with slurry-type bone graft, and does notaccommodate bone graft in granule form, which often varies in size amonggranules and does not have the same “flow” or viscosity characteristicsas slurry-type bone graft. Thus, the applicator of Mikhail isinsufficient for introducing most bone graft to a surgical site in apatient.

U.S. Pat. No. 6,019,765 issued to Thornhill et al. on Feb. 1, 2000(“Thornhill”) also teaches a bone graft delivery device. The bone graftdevice applicator of Thornhill is used to apply bone graft to anartificial joint without having to remove a previously implantedprosthesis component. The applicator device includes a hollow tube withan actuation mechanism for discharging the bone graft from the devicevia a nozzle coupled to a distal end of the tube. The bone graftdelivery device of Thornhill may include various components for loadingthe device with the bone graft, and may further include a plurality ofnozzles each having a geometry suited for a particular application. LikeMikhail, the Thornhill delivery device is designed for use with boneslurry, and requires much custom instrumentation and different sizedparts to achieve success in many bone graft delivery applications, whichin turn increases the time to assemble and use the delivery device andmay create further problems during the surgical operation.

U.S. Pat. No. 5,697,932 issued to Smith et al. on Dec. 16, 1997(“Smith”) discloses yet another bone graft delivery system and method.In Smith, a hollow tube of pre-loaded bone graft and a plunger are usedto facilitate delivery of the bone graft to a bone graft receiving area.A positioning structure is provided on the plunger to maintain theplunger in a desirable position with respect to the hollow tube. Adjunctpositioning means may also be provided to ensure that the plungerremains in the desirable position during the packing of bone graft intothe bone graft receiving area. Like the devices of Thornhill andMikhail, the device disclosed by Smith is clearly designed solely forslurry type bone graft, and does not provide an effective opening forreceiving the desired amount of bone graft. Furthermore, the hollow tubeshown by Smith is narrow and does not have a footing or other apparatusassociated with the delivery device for preventing the device frompenetrating, for example, the abdominal region of a patient, which mayoccur during tamping or packing of the bone graft. This in turn maycause serious injury to a patient if not controlled, and for thesereasons the device of Smith is also insufficient for delivery of bonegraft to a surgical site.

Traditional devices for inserting a fusion cage or other medicalimplants into a patient's spine or other surgical area are distinct andseparate from traditional devices that deliver bone graft material tothe surgical site. For example, once an implant has been positioned,then bone growth material is packed into the internal cavity of thefusion cage. Also, sometimes the process is reversed, i.e., the bonegrowth is inserted first, and then the implant. These bone growthinducing substances come into immediate contact with the bone from thevertebral bone structures which project into the internal cavity throughthe apertures. Two devices are thus traditionally used to insert bonegraft material into a patient's spine and to position and insert afusion cage. These devices thus necessitate a disc space preparationfollowed by introduction of the biologic materials necessary to inducefusion and, in a separate step, application of a structural interbodyfusion cage.

The problems associated with separate administration of the biologicmaterial bone graft material and the insertion of a fusion cage includeapplying the graft material in the path of the cage, restricting andlimiting the biologic material dispersed within the disk space, andrequiring that the fusion cage be pushed back into the same place thatthe fusion material delivery device was, which can lead to additionaltrauma to the delicate nerve structures.

Fusion cages provide a space for inserting a bone graft between adjacentportions of bone. Such cages are often made of titanium and are hollow,threaded, and porous in order to allow a bone graft contained within theinterior of the cage of grow through the cage into adjacent vertebralbodies. Such cages are used to treat a variety of spinal disorders,including degenerative disc diseases such as Grade I or IIspondylolistheses of the lumbar spine.

Surgically implantable intervertebral fusion cages are well known in theart and have been actively used to perform spinal fusion procedures formany years. Their use became popularized during the mid 1990's with theintroduction of the BAK Device from the Zimmer Inc., a specificintervertebral fusion cage that has been implanted worldwide more thanany other intervertebral fusion cage system. The BAK system is afenestrated, threaded, cylindrical, titanium alloy device that iscapable of being implanted into a patient as described above through ananterior or posterior approach, and is indicated for cervical and lumbarspinal surgery. The BAK system typifies a spinal fusion cage in that itis a highly fenestrated, hollow structure that will fit between twovertebrae at the location of the intervertebral disc.

Spinal fusion cages may be placed in front of the spine, a procedureknown as anterior lumbar interbody fusion, or ALIF, or placed in back ofthe spine. The cages are generally inserted through a traditional openoperation, though laparoscopic or percutaneous insertion techniques mayalso be used. Cages may also be placed through a posterior lumbarinterbody fusion, or PLIF, technique, involving placement of the cagethrough a midline incision in the back, or through a direct lateralinterbody fusion, or D-LIF, technique, involving placement of the cagethrough an incision in the side.

A typical procedure for inserting a common threaded and impacted fusioncage is as follows. First, the disc space between two vertebrae of thelumbar spine is opened using a wedge or other device on a first side ofthe vertebrae. The disk space is then prepared to receive a fusion cage.Conventionally, a threaded cage is inserted into the bore and the wedgeis removed. A disk space at the first side of the vertebrae is thenprepared, and a second threaded fusion cage inserted into the bore.Alternatively, the disk space between adjacent vertebrae may simply becleared and a cage inserted therein. Often, only one cage is insertedobliquely into the disk space. Use of a threaded cage may be foregone infavor of a rectangular or pellet-shaped cage that is simply insertedinto the disk space. Lastly, bone graft material may be inserted intothe surgical area using separate tools and devices.

U.S. Pat. No. 4,743,256 issued to Brantigan (“Brantigan”) discloses atraditional spinal back surgical method involving the implantation of aspinal fusion cage. The cage surfaces are shaped to fit within preparedendplates of the vertebrae to integrate the implant with the vertebraeand to provide a permanent load-bearing strut for maintaining the discspace. Brantigan teaches that these cages typically consist of ahomogeneous nonresorbable material such as carbon-reinforced polymerssuch as polyether ether ketone (PEEK) or polyether ketone ether ketoneketone (“PEKEKK”). Although these cages have demonstrated an ability tofacilitate fusion, a sufficient fusion is sometimes not achieved betweenthe bone chips housed within the cage and the vertebral endplates. Inparticular, achieving a complete fusion in the middle portion of thecage has been particularly problematic. As shown in FIG. 6 herein, theupper U and lower L surfaces of these cages C have large transversepores P which facilitate bone ingrowth, and these pores lead to an innervoid space IVS which houses bone graft (not shown) which facilitates thedesired fusion. In any case, Brantigan teaches the separate process andprocedure for the insertion of a fusion cage and the insertion of bonegraft. Indeed, local bone graft harvested from the channel cuts into thevertebrae to receive the plug supplements the fusion.

U.S. Pat. Appl. 20070043442 of Abernathie et al. (“Abernathie”)discloses another traditional spinal back surgical method involving theimplantation of a spinal fusion cage. Abernathie relates generally to animplantable device for promoting the fusion of adjacent bony structures,and a method of using the same. More specifically, Abernathie relates toan expandable fusion cage that may be inserted into an intervertebralspace, and a method of using the same. Abernathie includes an aperturein the fusion cage to allow bone growth therethrough, as a separateprocedure to the insertion of the fusion cage.

Traditional fusion cages are available in a variety of designs andcomposed of a variety of materials. The cages or plugs are commonly madeof an inert metal substrate such as stainless steel,cobalt-chromium-molybdenum alloys, titanium or the like having a porouscoating of metal particles of similar substrate metal, preferablytitanium or the like as disclosed, for example, in the Robert M. PilliarU.S. Pat. No. 3,855,683 issued Dec. 24, 1974 and U.S. Pat. No. 4,206,516issued Jun. 10, 1980. These plugs may take the form of flat sidedcubical or rectangular slabs, cylindrical rods, cruciform blocks, andthe like.

U.S. Pat. No. 5,906,616 issued to Pavlov et al. (“Pavlov”) discloses afusion cage of various cylindrical and conical shapes and a method ofinsertion. Like Brantigan, Pavlov teaches the separate process andprocedure for the insertion of a fusion cage and the insertion of bonegraft. U.S. Pat. No. 5,702,449 (“McKay”) discloses a spinal implantcomprising a cage made of a porous biocompatible material reinforced byan outer sleeve made of a second material which is relatively strongerunder the compressive load of the spine than the biocompatible material.U.S. Pat. No. 6,569,201 issued to Moumene et al. (“Moumene”) teaches abone fusion device having a structural bioresorbable layer disposed uponthe outer surface of a non-resorbable support. As the bioresorbablestructural layer resorbs over time, the load upon the bone graft housedwithin the non-resorbable support increases. Published PCT ApplicationNo. WO 99/08627 (“Gresser”) discloses a fully bioresorbable interbodyfusion device, as well as homogeneous composite devices containing atleast 25% resorbable materials. U.S. Pat. No. 7,867,277 issued to Tohmehdiscloses a spinal fusion implant of bullet shaped end.

U.S. Pat. No. 7,846,210 issued to Perez-Cruet et al. (“Perez-Cruet”)discloses an interbody device assembly consisting of a fusion device andan insertion device. The insertion device positions the fusion devicebetween two vertebrae, provides bone graft material, and then detachesfrom the fusion device, leaving the fusion device in place to restoredisc space height. However, the Perez-Cruet device is designed toreceive bone graft material from its insertion device and distribute thematerial away from the fusion device. In most embodiments of the fusiondevice, a center plate is positioned immediately downstream of thereceived bone graft material and directs the bone graft to opposingsides of the fusion device. (See, for example, FIG. 20 depicting plate308 directing bone graft material 392 along the exterior sides of thefusion device 302). As such, the Perez-Cruet fusion device is unlikelyto completely fill the areas near of its fusion cage and deliver bonegraft material to the surrounding bone graft site. Furthermore, none ofthe Perez-Cruet fusion device embodiments feature a defined interiorspace or a cage-style design. Indeed, the Perez-Cruet fusion deviceexplicitly teaches away from a contained-interior, fusion-cage-styledevice, asserting that its fusion device fills all of the disc space asopposed to a cage design, which contains the bone material. Furthermore,the Perez-Cruet does not feature a distal tip that functions toprecisely position the fusion device and stabilize the device duringdelivery of bone graft material.

U.S. Pat. No. 7,985,256 issued to Grotz et al. (“Grotz”) discloses anexpandable spinal implant for insertion between opposed vertebral endplates. The implant is a cylinder block of slave cylinders; a centralcavity between the cylinders receives bone graft material and pistonspositioned within the cylinders provide a corrective bone engagingsurface for expanding against a first vertebral end plate. The insertiontool used to place the spinal implant includes a handle and hollowinterior for housing hydraulic control lines and a bone graft supplyline. The Grotz system does not allow precise positioning or delivery ofbone graft material without an implant and requires a complex and bulkyinsertion tool.

U.S. Pat. Appl. 2010/0198140 to Lawson (“Lawson”) discloses a toolcomprising a cannula with an open slot at the distal end and a closedtip. Lawson's tool employs tamps to push bone aside and open up a voidfor filling; solid bone pellets are then rammed down the hollow interiorof the cannula by a tamper and delivered to the surgical site. Lawsondoes not allow precise positioning or delivery of viscous bone graftmaterial and has no capability to interconnect or integrate with animplant such as a bone graft fusion cage.

U.S. Pat. Appl. 2010/0262245 to Alfaro et al. (“Alfaro”) discloses adelivery system for an intervertebral spacer and a bone graftingmaterial comprising a spacer disengagingly attached to a hollow handle.The handle comprises a chamber and bone grafting material-advancingmeans for introducing bone grafting material from the chamber into thespacer and the intervertebral spaces. The Alfaro system does not allowprecise positioning or delivery of bone graft material through a distaltip that precisely positions the fusion device and stabilizes the deviceduring delivery of bone graft material, and does not allow primarilylateral injection of bone graft fusion material.

The prior art bone graft delivery devices listed above typically mustcome pre-loaded with bone graft, or alternatively require constantloading (where permissible) in order to constantly have the desiredsupply of bone graft available. Moreover, these bone graft deliverydevices generally cannot handle particulate bone graft of varying orirregular particulate size. Furthermore, the prior art devices forinserting a fusion cage or other medical implant into a patient's spineor other surgical area are commonly distinct and separate fromtraditional devices that deliver bone graft material to the surgicalsite. As such, two devices are traditionally used to insert bone graftmaterial into a patient's spine and to position and insert a fusioncage. The problems associated with separate administration of thebiologic material bone graft material and the insertion of a fusion cageinclude applying the graft material in the path of the cage, restrictingand limiting the biologic material dispersed within the disk space, andrequiring that the fusion cage be pushed back into the same place thatthe fusion material delivery device was, which can lead to additionaltrauma to the delicate nerve structures. These problems can be a greatinconvenience, cause avoidable trauma to a patient and make these priorart devices unsuitable in many procedures.

Therefore, there is a long-felt need for an apparatus and method fornear-simultaneous and integrated precision delivery of bone graftmaterial during the placement of surgical cages or other medicalimplants in a patient's spine. The present invention solves these needs.The present invention allows biologic material to flow directly to thefusion cage and be dispersed within the disc space in a single step, andcan precisely and simply deliver particulate bone graft of varying orirregular particulate size. Thus, the present invention allowsapplication of bone graft material through a detachable fusion cage,eliminates otherwise restriction of the volume of biologic material thatmay be dispersed within the disk space, and eliminates the requirementthat the fusion cage be pushed back into the same place that the fusionmaterial delivery device was, which can lead to additional trauma to thedelicate nerve structures.

SUMMARY OF THE INVENTION

Certain embodiments of the present disclosure relate to an apparatus andmethod for near-simultaneous and integrated delivery of bone graftmaterial during the placement of surgical cages or other medicalimplants in a patient's spine. The integrated fusion cage and deliverydevice (the “device”) is comprised generally of a tubular member and aplunger for expelling bone graft from the tubular member, through asurgical fusion cage, and into a bone graft receiving area, thendisengaging the fusion cage at the surgical site in a human patient.Thus, the apparatus and method allows the biologic material to flowdirectly into and through the fusion cage and dispersed within the discspace in a single step, and leave the detachable fusion cage in thesurgical area. Other embodiments and alternatives to this device aredescribed in greater detail below.

By way of providing additional background, context, and to furthersatisfy the written description requirements of 35 U.S.C. §112, thefollowing references are incorporated by reference in their entiretiesfor the express purpose of explaining the nature of the surgicalprocedures in which bone graft is used and to further describe thevarious tools and other apparatus commonly associated therewith: U.S.Pat. No. 6,309,395 to Smith et al.; U.S. Pat. No. 6,142,998 to Smith etal.; U.S. Pat. No. 7,014,640 to Kemppanien et al.; U.S. Pat. No.7,406,775 to Funk, et al.; U.S. Pat. No. 7,387,643 to Michelson; U.S.Pat. No. 7,341,590 to Ferree; U.S. Pat. No. 7,288,093 to Michelson; U.S.Pat. No. 7,207,992 to Ritland; U.S. Pat. No. 7,077,864 Byrd III, et al.;U.S. Pat. No. 7,025,769 to Ferree; U.S. Pat. No. 6,719,795 to Cornwall,et al.; U.S. Pat. No. 6,364,880 to Michelson; U.S. Pat. No. 6,328,738 toSuddaby; U.S. Pat. No. 6,290,724 to Marino; U.S. Pat. No. 6,113,602 toSand; U.S. Pat. No. 6,030,401 to Marino; U.S. Pat. No. 5,865,846 toBryan, et al.; U.S. Pat. No. 5,569,246 to Ojima, et al.; U.S. Pat. No.5,527,312 to Ray; and U.S. Pat. Appl. No. 2008/0255564 to Michelson.

By way of providing additional background, context, and to furthersatisfy the written description requirements of 35 U.S.C. §112, thefollowing references are incorporated by reference in their entiretiesfor the express purpose of explaining the nature of the surgicalprocedures in which fusion cages are used and to further describe thevarious tools and other apparatus commonly associated therewith: U.S.Pat. No. 6,569,201 to Moumene et al.; U.S. Pat. No. 6,159,211 to Borianiet al.; U.S. Pat. No. 4,743,256 to Brantigan; U.S. Pat. Appl.2007/0043442 to Abernathie et al.; U.S. Pat. Nos. 3,855,683 and4,206,516 to Pilliar; U.S. Pat. No. 5,906,616 issued to Pavlov et al.;U.S. Pat. No. 5,702,449 to McKay; U.S. Pat. No. 6,569,201 to Moumene etal.; PCT Appl. No. WO 99/08627 to Gresser; U.S. Pat. Appl. 2012/0022651to Akyuz et al.; U.S. Pat. Appl. 2011/0015748 to Molz et al.; U.S. Pat.Appl. 2010/0249934 to Melkent; U.S. Pat. Appl. 2009/0187194 to Hamada;U.S. Pat. No. 7,867,277 issued to Tohmeh; U.S. Pat. No. 7,846,210 toPerez-Cruet et al.; U.S. Pat. No. 7,985,256 issued to Grotz et al.; U.S.Pat. Appl. 2010/0198140 to Lawson; and U.S. Pat. Appl. 2010/0262245 toAlfaro et al.

By way of providing additional background and context, the followingreferences are also incorporated by reference in their entireties forthe purpose of explaining the nature of spinal fusion and devices andmethods commonly associated therewith: U.S. Pat. No. 7,595,043 issued toHedrick et al.; U.S. Pat. No. 6,890,728 to Dolecek et al.; U.S. Pat. No.7,364,657 to Mandrusov, and U.S. Pat. No. 8,088,163 to Kleiner.

In addition, by way of providing additional background and context, thefollowing references are also incorporated by reference in theirentireties for the purpose of explaining the nature of spinal fusion anddevices and methods commonly associated therewith: US Pat. No. D647,202entitled “Bone Marrow Harvesting Device” to Scifert issued Oct. 18,2011; U.S. Pat. No. 7,897,164 entitled “Compositions and Methods forNucleus Pulposus Regeneration” to Scifert issued Mar. 1, 2011; US Pat.Appl. No. 2010/0112029 entitled “Compositions and Methods for NucleusPulposus Regeneration” to Scifert issued May 6, 2010; US Pat. Appl. No.2010/0021518 entitled “Foam Carrier for Bone Grafting” to Scifert issuedJan. 28, 2010; U.S. Pat. No. 7,824,703 entitled “Medical Implants withReservoir(s), and Materials Preparable From Same” to Scifert, et al.,issued Nov. 2, 2010; US Pat. Appl. No. 2006/0247791 entitled“Multi-Purpose Medical Implant Devices” to McKay, et al., issued Nov. 2,2006; US Pat. Appl. No. 2007/0225811 entitled “Conformable OrthopedicImplant” to Scifert, et al., issued Sep. 27, 2007; U.S. Pat. No.6,746,487 entitled “Intramedullary Trial Fixation Device” to Scifert, etal., issued Jun. 9, 2004; US Pat. Appl. No. 2013/0073041 entitled“Medical Implants With Reservoir(s), and Materials Preparable From Same”to Scifert et al., issued Mar. 21, 2013; US Pat. Appl. No. 2010/0266689entitled “Tissue Augmentation With Active Agent For Wound Healing” toSimonton et al., issued Oct. 21, 2010; US Pat. Application No.2011/0028393 entitled “Flowable Paste And Putty Bone Void Filler” toVickers et al., issued Feb. 3, 2011; US Pat. Appl. No. 2009/0099660entitled “Instrumentation To Facilitate Access Into The IntervertebralDisc Space And Introduction Of Materials Therein” to Scifert issued Apr.16, 2009; US Pat. Appl. No. 2011/0014587 entitled “System And Methods OfPreserving An Oral Socket” to Spagnoli et al., issued Jan. 20, 2011;U.S. Pat. No. 8,148,326 entitled “Flowable Carrier Matrix and Methodsfor Delivering to a Patient” to Beal et al., issued Apr. 3, 2012; USPat. Appl. No. 2008/0260598 entitled “Devices, Methods and Systems forHydrating a Medical Implant Material” to Gross et al., issued Oct. 23,2008; US Pat. Appl. No. 2007/0265632 entitled “Bone Cutting Template andMethod of Treating Bone Fractures” to Scifert et al., issued Nov. 15,2007; U.S. Pat. No. 8,293,232 entitled “Flowable Carrier Matrix andMethods for Delivering to a Patient” to Beals et al., issued Oct. 23,2012; U.S. Pat. No. 8,198,238 entitled “Flowable Carrier Matrix andMethods for Delivering to a Patient” to Beals et al., issued Jun. 12,2012; U.S. Pat. No. 7,939,092 entitled “Cohesive Osteogenic Putty andMaterials Therefor” to McKay et al., issued May 10, 2011; US Pat. Appl.No. 2007/0264300 entitled “Therapeutic Agent Carrier and Method ofTreating Bone Fractures” to Scifert et al., issued Nov. 15, 2007; USPat. Appl. No. 2011/0020768 entitled “Implantable Screw and System forSocket Preservation” to Spagnoli et al., issued Jan. 27, 2011; US Pat.Appl. No. 2012/0065687 entitled “Multi-Radius Vertebral Rod with aVarying Stiffness” to Ballard et al., issued Mar. 15, 2012; US Pat. No.2007/0225219 entitled “Intramedullary Drug Delivery Device and Method ofTreating Bone Fractures” to Boden et al., issued Sep. 27, 2007; U.S.Pat. No. 7,723,291 entitled “Release of BMP, Bioactive Agents and/orCells Via a Pump into a Carrier Matrix” to Beals et al., issued May 25,2010; U.S. Pat. No. 7,671,014 entitled “Flowable Carrier Matrix AndMethods For Delivering To A Patient” to Beals et al., issued Mar. 2,1010; U.S. Pat. No. 7,897,564 entitled “Flowable Carrier Matrix andMethods for Delivering to a Patient” to Beals et al., issued Mar. 1,2011; US Pat. Application No. 2011/0160777 entitled “System and Methodsof Maintaining Space for Augmentation of the Alveolar Ridge” to Spagnoliet al., issued Jun. 30, 2011; US Pat. Application No. 2009/0246244entitled “Malleable Multi-Component Implants and Materials Therefor” toMcKay et al., issued Oct. 1, 2009; US Pat. Application No. 2009/0246244entitled “Malleable Multi-Component Implants and Materials Therefor” toMcKay et al., issued Oct. 1, 2009; US Pat. No. 2013/0110169 entitled“Vertebral Rod System and Methods of Use” to Hynes, et al., issued May2, 2013; US Pat. Appl. No. 2011/0184412 entitled “Pre-AssembledConstruct With One Or More Non-Rotating Connectors For Insertion Into aPatient” to Scifert, et al., issued Jul. 28, 2011; U.S. Pat. No.7,964,208 entitled “System and Methods of Maintaining Space ForAugmentation of the Alveolar Ridge” to Spagnoli, et al., issued Jun. 21,2011; U.S. Pat. No. 8,080,521 entitled “Flowable Carrier Matrix andMethods for Delivering to a Patient” to Beals, et al., issued Dec. 20,2011; US Pat. Appl. No. 2009/0142385 entitled “Compositions for TreatingBone Defects” to Gross, et al., issued Jun. 4, 2009; U.S. Pat. No.7,578,820 entitled “Devices and Techniques for a Minimally Invasive DiscSpace Preparation and Implant Insertion” to Moore, et al., issued Aug.25, 2009; US Pat. Appl. No. 2010/0305575 entitled “Methods and Apparatusfor Performing Knee Arthroplasty” to Wilkinson, et al., issued Dec. 2,2010; US Pat. Appl. No. 2011/0021427 entitled “Biphasic CalciumPhosphate Cement for Drug Delivery” to Amsden, et al., issued Jan. 27,2011; US Pat. Appl. No. 2012/0259335 entitled “Patello-Femoral JointImplant and Instrumentation” to Scifert, et al., issued Oct. 11, 2012;US Pat. Appl. No. 2011/0106162 entitled “Composite Connecting Elementsfor Spinal Stabilization Systems” to Ballard, et al., issued May 5,2011; US Pat. Appl. No. 2004/0073314 entitled “Vertebral Body and DiscSpace Replacement Devices” to White, et al., issued Apr. 15, 2004; U.S.Pat. No. 7,513,901 entitled “Graft Syringe Assembly” to Scifert, et al.,issued Apr. 7, 2009; US Pat. Appl. No. 2010/0004752 entitled “VertebralBody and Disc Space Replacement Devices” to White, et al., issued Jan.7, 2010; U.S. Pat. No. 7,615,078 entitled “Vertebral Body and Disc SpaceReplacement Devices” to White, et al., issued Nov. 10, 2009; U.S. Pat.No. 6,991,653 entitled “Vertebral Body and Disc Space ReplacementDevices” to White, et al., issued Jan. 31, 2006; US Pat. Appl. No.2010/0331847 entitled “Methods and Apparatus for Performing KneeArthroplasty” to Wilkinson, et al., issued Dec. 30, 2010; US Pat. Appl.No. 2006/0116770 entitled “Vertebral Body and Disc Space ReplacementDevices” to White, et al., issued Jun. 1, 2006; and U.S. Pat. No.8,246,572 entitled “Bone Graft Applicator” to Cantor, et al., issuedAug. 21, 2012.

According to varying embodiments described herein, the present inventionis directed to near-simultaneous and integrated delivery of bone graftmaterial during the placement of surgical cages or other medicalimplants into a patient's spine. The delivery of the bone graft materialmay be to any area of the body, and in particular to the intervetebraljoints of the spine, for achieving bone graft fusion. The device may beused without the optional near-simultaneous and integrated placement ofsurgical cages with the delivery of bone graft material. Also, theinvention may be used in the repair of a bone joint or in connectionwith the implantation of prosthetic devices in the body, including, byway of example but not limitation, the hip, knee and a variety of spinaljoints. Additionally, the present invention may be used in primarysurgery, in which a bone graft is being supplied to promote new bonegrowth or to reconstruct a joint for the first time, as well as inrevision surgery, in which a follow-up procedure is being performed inan area that has previously been subject to one or more surgeries.Further, the invention may be used in any application where material isto be delivered with precision to a confined area where access isrestricted, to include surgical procedures, repair of installed oruninstalled mechanical or electrical devices, and arming or disarming ofexplosive devices.

Although well suited for use in human patients, and although much of thediscussion of the present invention is directed toward use in humans,advantages offered by the present invention may be realized in theveterinary and scientific fields for the benefit and study of all typesof animals and biological systems. Additionally, although the fusioncages of the present invention are particularly well-suited forimplantation into the spinal column between two target vertebrae, andalthough much of the discussion of the present invention is directedtoward their use in spinal applications, advantages offered byembodiments of the present invention may also be realized byimplantation at other locations within a patient where the fusion of twoor more bony structures may be desired. As one of skill in the art willappreciate, the present invention has applications in the general fieldof skeletal repair and treatment, with particular application to thetreatment of spinal injuries and diseases. It should be appreciated,however that the principles of the present invention can also findapplication in other areas, specifically where there is a desire toconstrain added fluid material to particular regions. For example, thepresent invention finds application in methods where the objective is toconfine added material to predetermined areas of interest and toprohibit the undesired translocation of such material until an operationis complete and/or until a predetermined later time.

According to various embodiments of the present disclosure, one aspectof the invention is to provide an integrated fusion cage and graftdelivery device that comprises a tubular member, which is substantiallyhollow or contains at least one inner lumen and that has a generallyrectangular cross-sectional shape. This generally rectangularcross-sectional shape offers a larger amount of surface area throughwhich bone graft material may be inserted and ejected from the hollowtubular member. Furthermore, this generally rectangular shape is morecongruent with the size or shape of the annulotomy of most disc spaces,which frequently are accessed by a bone graft delivery device fordelivery of bone graft. However, as one skilled in the art wouldappreciate, the tool cross-section need not be limited to a generallyrectangular shape. For example, cross-sections of an oval shape or thosewith at least one defined angle to include obtruse, acute, and rightangles can provide a shape in some situations that is more congruentwith the size or shape of the annulotomy of a particular disc space. Asubstantially round shape may also be employed that provides the surgeonwith an indication of directional orientation.

The phrase “removably attached” and/or “detachable” is used herein toindicate an attachment of any sort that is readily releasable.

The phrase “integrated fusion cage”, “spinal fusion implant”,“biological implant” and/or “fusion cage” is used here to indicate abiological implant.

According to various embodiments of the present disclosure, it isanother aspect that the hollow tubular member further comprise at leastone opening on a lateral face or surface of the hollow tubular member,at one distal end, for ejecting bone graft material into a bone graftreceiving area, such as a disc space, such that the bone graft materialis ejected from the hollow tubular member through an additional implant,such as a structural cage implant. In addition, the graft material isdispersed into the area of the debrided disc space surrounding andwithin the cage. Furthermore, the structural cage implant is removablyattached to the hollow tubular member so as to be deposited into thesurgical area. Thus, the device may be used in an integrated andnear-simultaneous method for depositing bone graft material into adebrided disc space through a structural cage implant and leaving thestructural implant.

According to various embodiments of the present disclosure, one aspectof the invention is to provide an integrated fusion cage detachablecomponent of the integrated fusion cage and graft delivery device thatcomprises a biological implant that fits over the distal end of thesubstantial hollow tube, and which has a shape that is substantiallycongruent with the distal end of the hollow tube. However, the shape andconfiguration of the integrated fusion cage need not be limited to agenerally rectangular shape. For example, cross-sections of an ovalshape or those with at least one defined angle to include obtruse,acute, and right angles can provide a shape in some situations that ismore congruent with the size or shape of the annulotomy of a particulardisc space. A substantially round shape may also be employed thatprovides the surgeon with an indication of directional orientation.

In a preferred embodiment, the fusion cage has a tapered tip, andseveral open channels along the medial surfaces. In a preferredembodiment, the fusion cage and/or the bone graft delivery portion ofthe integrated fusion cage and graft delivery device is of oblong orrectangular, or square shape. The integrated fusion cage and graftdelivery device is designed to avoid blocking or impacting bone graftmaterial into a surgical disc space, thereby limiting the bone graftmaterial that may be delivered, and not allowing available fusion spaceto be fully exploited for fusion.

In a preferred embodiment, the fusion cage has a keel-shaped tip toseparate disk and prevent annular penetration. Also, the fusion cage hasdual portals for bone graft discharge, with the medial openings largerthan the lateral openings. Further, the fusion cage may be designed invariable heights and lengths so that it fits snugly into the prepareddisk space.

In a preferred embodiment that is ideal for anterior lumbar interbodyfusion, the fusion cage has two portals for bone graft dischargepositioned on opposite sides of the fusion cage. In a preferredembodiment that is ideal for direct lateral interbody fusion, the fusioncage has six portals for bone graft discharge, with three portals on oneside of the fusion cage and three portals on an opposite side of thefusion cage. And, in a preferred embodiment that is ideal forpost-vertebrectomy use, two opposing wall portions of the fusion cageare substantially porous to bone graft slurry, while the substantialremainder of the wall of the fusion cage is substantially impervious tobone graft slurry.

In another embodiment of the device, the hollow tube engages with thefusion cage via a break-off collar and the plunger inserts into theinterior of the hollow tube. The break-off collar may be severed by anyof several means, to include application of torsion and/or rotationalforce and/or lateral force to the break-off collar, for example bytwisting on the hollow tube and/or the plunger. The break-off collar maybe formed by any of several means, comprising a thinner and/or reducedcross-sectional, that is thickness, a pre-set fracture-line, one or morenotches, a frangible portion defined by a discrete, extended area thatis weaker in one or more respects as compared to surrounding and/oradjacent material, and any means known to those skilled in the art toachieve reliable break-off Preferably a clean break is achieved suchthat no surgically significant issues arise so such severance of thecage-portion and the hollow for the portion. In other embodiments, otherways devices and features can be employed to achieve separation of orfirst delivery tube structure and a second structure intended to remainin a patient. For example, electric and/or magnetic disconnectingmechanisms can be used in lieu of a physical breaking/severing of twodiscrete portions that define the above-referenced first and secondstructures. A smooth edge preferably remains after such severance of thecage. Moreover, it will be understood as being within the scope of thepresent invention to use more conventional coupling/decouplingmechanisms to achieve desired separation of the first and secondstructures, e.g. bayonette mounted features, tongue and groove,male/female interlocking structures, clamping devices, nestedarrangements, etc., all of which find support in the various citedreferences incorporated herein by reference. In one example method ofuse, the connected hollow tube and fusion cage is inserted into thesurgical area, bone graft material is inserted into the hollow tube (oralready provided as a pre-packaged material), the plunger is pushed intothe hollow tube, so as to deliver bone graft material to the site, thenthe plunger is reversed or pulled-out so to retreat from the site andmove higher or beyond the break-off collar, and then the break-offcollar is broken so as to disengage the fusion cage from the hollow tubeand therein leave the fusion cage at the surgical site. In anotherembodiment of the device, the hollow tube engages with a connectorconduit which in turn connects with the fusion cage via a break-offcollar. One or more connectors connect the hollow tube with theconnector conduit. The hollow tube fits over the connector conduit. Theone or more connectors fit through the hollow tube and the connectorconduit. Alternately, the hollow tube may fit over the connector conduitvia a press-fit, aka interference fit, without need of one or moreconnectors. In one embodiment, the connectors comprise set screws, pinsand tabs. The connector conduit allows, for example, various fusioncages designs to be fitted to a common hollow tube/plunger combination.This allows, for example, the common hollow tube/plunger combination tobe re-sterilized and thus reused in multiple surgical procedures. In oneembodiment, the hollow tube/plunger combination is re-usable and thefusion cage is disposable.

In one embodiment of the connector conduit, the connector conduit is ofcircular cross-section. In another embodiment, the connector conduit isof conical shape, or any shape that allows a transition in diameterbetween the fusion cage and the follow tube.

In one example method of use, the hollow tube is inserted over theconnection conduit (which is attached to the fusion cage), then insertedinto the surgical area, bone graft material is inserted into the hollowtube (or already provided as a pre-packaged material), the plunger ispushed into the hollow tube (and past the connection conduit), so as todeliver bone graft material to the site, then the plunger is reversed orpulled-out so to retreat from the site and move higher or beyond thebreak-off collar, and then the break-off collar is broken so as todisengage the fusion cage from the hollow tube (which is still connectedto the connection conduit) and therein leave the fusion cage at thesurgical site.

The break-off collar may be severed by any of several means, to includeapplication of torsion and/or rotational force and/or lateral force tobreak-off collar, for example by twisting on the hollow tube and/or theplunger.

In one embodiment of the fusion cage, the fusion cage is of rectangularcross-section, such that one pair of opposite sides, for example aheight first pair of sides, has a dimension of approximately 8-14 mm,and a second pair of opposite sides, for example a length dimension, ofapproximately 22-36 mm. One skilled in the art will appreciate that theexact dimensions of the fusion cage may be adapted to conform toparticulars of the surgical site, for example, the relative sizingbetween the particular vertebrae in which bone graft material and/or afusion cage is to be inserted. In other embodiments of the fusion cage,the fusion cage is of a substantially cylindrical shape. For example, apreferred embodiment of a fusion cage for use in an ALIF procedure formsa substantially cylindrical shape, with a height of approximately 8-14mm and a diameter of less than about 36 millimeters. As another example,a preferred embodiment of a fusion cage for use in conjunction with avertebrectomy has a substantially cylindrical shape with a height equalto or greater than the height of the vertebra (or the collective heightof the vertebrae) it is intended to replace and a diameter of less thanabout 36 millimeters. Preferably, the separation “zone” between the cageand the hollow filling tube is at one end of the cage, preferably theend of the cage (when implanted) closer to the incision site.

A preferred method of using the integrated fusion cage and graftdelivery device comprises precisely inserting the integrated fusion cageand graft delivery device, in one or more of the embodiments containedherein, into the surgical area. The integrated fusion cage and graftdelivery device is then filled with bone graft material in its one ormore substantially hollow tubes, the one or more plungers are insertedinto the one or more hollow tubes, and the one or more plunger arepushed into the one or more hollow tubes, guided precisely as enabled bythe minimal profile of the device, therein controllably depositing thebone graft material into the surgical area through and into the surgicalimplant cage. The surgical implant device may then be selectablydetached from the integrated fusion cage and graft delivery device so asto remain at the surgical site.

Another method of using the integrated fusion cage and graft deliverydevice comprises inserting the integrated fusion cage and graft deliverydevice into a prepared disk space, such that the fusion cage portionfits snugly into the prepared disk space (the fusion cage is designed invariable heights and lengths so as to fit snugly into the prepared diskspace), pushing the plunger through the hollow shaft so as to pushbiological fusion material (e.g. bone graft) through the hollow shaft toflow the biological material through the fusion cage's open lateraland/or medial portals in communication with the hollow tube and plunger,thereby delivering biological material into the prepared disk space,after which the fusion cage is detached from the hollow tube and left inthe disk space. Thus, the fusion cage is left in the disk space with amaximum and/or optimal amount of biological material near-simultaneouslydelivered within the fusion cage and/or surrounding the fusion cage inthe disk space.

Using the integrated fusion cage and graft delivery device as describedovercomes a problem associated with the traditional separate applicationof bone graft material and insertion of a fusion cage. Specifically, inthe traditional method, the volume of disk space which does not containbone graft material is limited, which, for example, limits theeffectiveness of the surgical procedure. For example, using thetraditional two-step procedure, bone graft may be inserted into, forexample, a cylindrically-shaped area of radius r to a height h of 8 mm,and then a cylindrically-shaped fusion cage inserted of height h of 14mm. Thus, the surgical area is left without a complete volume of bonegraft material, i.e. because the volume of a cylinder is Volume=πr² h,the bone graft area is left without πr² (14 mm-8 mm), or 6πr² of bonegraft material. (Note that this represents a 75% increase in bone graftmaterial delivered to the surgical site for these example dimensions).This effectively dilutes the bone graft material and reduces itseffectiveness. The present invention can substantially or completelyfill the available disk space with bone graft material, becausedistraction of the disk space is performed substantially simultaneouslywith application of the fusion cage. Because more biological material isdelivered to the prepared disk space, the fusion rate should increase.Also, by directly implanting fusion material, e.g. bone graft material,though a fusion cage positioned for detachment (and then detached) as asingle step, time is saved and there is less manipulation of thesensitive nerve tissue at the fusion site (which increases safety).

Furthermore, the integrated fusion cage and graft delivery device may beused without the surgical implant delivery device portion such that themethod comprises precisely inserting the integrated fusion cage andgraft delivery device, in one or more of the embodiments containedherein, into the surgical area that may already contain one or moreadditional implants, such as a structural cage implant. The integratedfusion cage and graft delivery device is then filled with bone graftmaterial in its one or more substantially hollow tubes, the one or moreplungers are inserted into the one or more hollow tubes, and the one ormore plunger are pushed into the one or more hollow tubes, guidedprecisely as enabled by the minimal profile of the device, thereincontrollably depositing the bone graft material into the surgical areawithout depositing bone graft material into the path of any structuralcage implant or other implant that may already be present.

According to a still further aspect of the present invention, theintegrated fusion cage may be introduced into a spinal target sitewithout the use of the graft delivery device that is through use of anyof a variety of suitable surgical instruments having the capability toengage the implant. The integrated fusion cage is capable of being usedin minimally invasive surgical procedures, needing only a relativelysmall operative corridor for insertion.

According to a still further aspect of the present invention, theintegrated fusion cage of the present invention may be used in a varietyof configurations in a fusion procedure, including but not limited to(and by way of example only) unilateral, paired unilateral andbilateral.

Furthermore, the integrated fusion cage and graft delivery device andmethod of use is applicable to position and deliver fusion cages fromthe side, directly anterior or in the anterior fusion cages of thecervical spine.

In a preferred embodiment, the integrated fusion cage and graft deliverydevice comprises a hollow tube or contains at least one inner lumenconstructed to receive bone graft, and a plunger adapted for insertionat least partially within the hollow tube and preferably through thefull extent of the hollow tube. The plunger of some embodiments isgenerally of the same geometric configuration as the hollow interiorportion of the hollow tube so that the plunger, once fully inserted into the hollow tube, is substantially congruent with the hollow interiorportion of the hollow tube, e.g. both the plunger and the hollow tubeare substantially the same shape and/or class. The plunger preferablyextends about the same length as the hollow tube, and further comprisesan end portion, e.g. at least one knob or handle for grasping andmanipulation by a user, or in robotic or automated or semi-automatedcontrol or surgeries, by a machine.

Also according to a preferred embodiment, the hollow interior portion ofthe hollow tube further comprises a sloped or curved surface at a secondend (e.g. positioned near a place for deposit of bone graft material)adjacent and opposite a lateral window or opening in a lateral face ofthe hollow tube. As the interior of the hollow tube comprises a slopedor curved surface at its second end, the plunger also comprises a slopedor curved surface at a second end of the plunger. The plunger terminatesopposite the curved surface at its second end with a laterally facedsurface, which corresponds to the lateral window or opening at thesecond end of the hollow tube. The distal end of the hollow tube isfitted with a substantially conformal fusion cage that covers theexterior surface of the hollow tube, fitted with one or more openingsthat align with one or more openings of the hollow tube. Thus, incooperation, the plunger may be inserted into the opening of the hollowtube, and extended the entire length of the hollow tube, at least to apoint where the laterally faced surface of plunger is in communicationwith the lateral window or opening at the second end of the hollow tube.This configuration permits a user to eject substantially all of the bonegraft material that is placed into the hollow tube in a lateraldirection at the bone graft receiving area, through the substantiallyconformal and detachable fusion cage that covers the exterior surface ofthe hollow tube, optionally detach the detachable fusion cage, during asurgical procedure.

In a preferred embodiment, the integrated fusion cage and graft deliverydevice comprises an integrated fusion cage that comprises a firstproximal end and a second distal end, wherein the first proximal endcontains an opening adapted to allow fitting and/or engagement to thedistal end of the hollow tube. This fitting and/or engagement may beover the external surface of the hollow tube or inside the interior ofthe hollow tube. Further, the integrated fusion cage may comprise one ormore medial openings and one or more lateral openings that align withone or more openings at the distal end of the hollow tube. Further, theintegrated fusion cage may contain surfaces, such as belts orstriations, along one or more medial surfaces of the integrated fusioncage. The integrated fusion cage is configured such that when a plunger,once fully inserted in to the hollow tube, is substantially congruentwith the hollow interior portion of the hollow tube, e.g. both theplunger and the hollow tube are substantially the same shape and/orclass and bone graft material is delivered through the integrated fusioncage into the surgical area.

In one embodiment, a substantially hollow implant is detachablyinterconnected to a distal end of the hollow tube, the implant having aproximal end and a tapered distal end, the tapered distal end having anexterior tapered surface and a tapered interior surface, and the plungeradapted for inserting into the proximal end of the hollow tube, theplunger having a tapered distal end being contoured to the taperedinterior surface of the distal end of the implant to form a conformingfit between the tapered distal end of the plunger and the taperedinterior surface of the distal end of the implant when the plunger isfully inserted into the implant such that bone graft material within thehollow tube is delivered to a graft receiving area through at least oneopening of the implant. Further, the distal end of the implant maycomprise a closed distal tip, and the tapered distal end of the plungermay be wedge-shaped and the tapered interior surface of the closeddistal tip of the distal end of the implant may be wedge-shaped.

The spinal fusion implant of the present invention may be used toprovide temporary or permanent fixation along an orthopedic target site.

The spinal fusion implant of the present invention may be provided withany number of additional features for promoting fusion, such as one ormore apertures extending between the top and bottom surfaces which allowa boney bridge to form through the spinal fusion implant.

The spinal fusion implant may also be provided with any number ofsuitable anti-migration features to prevent the implant from migratingor moving from the disc space after implantation. Suitableanti-migration features may include, but are not necessarily limited to,angled teeth or ridges formed along the top and bottom surfaces of theimplant and/or rod elements disposed within the distal and/or proximalends.

According to a further aspect of the present invention, the spinalfusion implant may be provided with one or more radiographic markers atthe proximal and/or distal ends. These markers allow for a more detailedvisualization of the implant after insertion (through radiography) andallow for a more accurate and effective placement of the implant.

According to a still further aspect of the present invention, the distalend of the spinal fusion implant may have a conical (bullet-shaped)shape including a pair of first tapered (angled) surfaces and a pair ofsecond tapered (angled) surfaces. The first tapered surfaces extendbetween the lateral surfaces and the distal end of the implant, andfunction to distract the vertebrae adjacent to the target intervertebralspace during insertion of the spinal fusion implant. The second taperedsurfaces extend between the top and bottom surfaces and the distal endof the spinal fusion implant, and function to maximize contact with theanterior portion of the cortical ring of each adjacent vertebral body.Furthermore, the second tapered surfaces provide for a better fit withthe contour of the vertebral body endplates, allowing for a moreanterior positioning of the spinal fusion implant and thus advantageousutilization of the cortical rings of the vertebral bodies.

Another embodiment for the integrated fusion cage and graft deliverydevice comprises a detachable fusion cage that is detachable, orremovably attached, by any of several means. As disclosed above, in oneembodiment, the fusion cage is substantially conformal with the distalend of the hollow tube in that it covers the exterior surface of thehollow tube, wherein the fusion cage is configured with one or moreopenings that align with one or more openings of the hollow tube. In onepreferred embodiment, the fusion cage of the integrated fusion cage andgraft delivery device forms an interference fit with the fusion cage,such that when the integrated fusion cage and graft delivery device isinserted into the surgical area, the integrated fusion cage and graftdelivery device presses against bone and/or vertebrates such that whenan axial force is applied to the integrated fusion cage and graftdelivery device in a rearward direction (toward the proximal end of theintegrated fusion cage and graft delivery device), the fusion cagedetaches from the integrated fusion cage and graft delivery device andthereby remains in the surgical area.

In another embodiment for the integrated fusion cage and graft deliverydevice and its method of use, the fusion cage is substantially filledwith bone graft material after the fusion cage is implanted. In anotherembodiment for the integrated fusion cage and graft delivery device andits method of use, the fusion cage is substantially filled with bonegraft material simultaneously with the implantation of the fusion cage.

In another embodiment for the integrated fusion cage and graft deliverydevice and its method of use, the fusion cage and/or the bone graftmaterial associated with the fusion cage may be accessed duringsubsequent surgical operations.

In another embodiment for the integrated fusion cage and graft deliverydevice and its method of use, the fusion cage is a separate device, forexample a pre-packaged implant device, which may be installedindependently from the integrated fusion cage and graft delivery deviceor installed in coordination with the integrated fusion cage and graftdelivery device. In either situation, the device may be used to providebone graft material in and/or around the pre-packaged implant.

In another embodiment for the integrated fusion cage and graft deliverydevice and its method of use, some or all of the bone graft material isprovided as a component of a per-packaged implant. In another embodimentfor the integrated fusion cage and graft delivery device, the detachablefusion cage is detachable by way of a indent-tab that penetrates theinterior of the hollow tube, such, when the plunger is substantiallyinserted into the hollow tube, the indent-tab is pushed out from theinterior of the hollow tube so as to no longer be attached to theintegrated fusion cage and graft delivery device, thereby remaining inthe surgical area.

In another embodiment, the hollow tube is of cylindrical shape andincludes one or more locking tabs or indent tabs configured to engageone or more locking slots of the fusion cage. The locking tabs maypermanently or not permanently engage the locking slots, and may be of ashape to include rectangular, circular and oblong. In one embodiment ofthe locking tabs and locking slots, the locking tabs and locking slotsengage one another by rotating the hollow tube clockwise and arereleased by counterclockwise rotation. In another embodiment of theconfiguration of the locking tabs and locking slots, the locking tabsand locking slots engage one another by rotating the hollow tubecounterclockwise and are released by clockwise rotation.

In another embodiment, the fusion cage has internal ramps which assistin directing the bone graft material to one or more openings in thefusion cage.

In another embodiment for the integrated fusion cage and graft deliverydevice, the detachable fusion cage is detachable by way of receipt of anelectrical, mechanical, pneumatic, hydraulic or other communicationimparted by the user upon the plunger and/or hollow tube so as to detachthe fusion cage and thereby deposit the fusion cage into the surgicalarea.

In another embodiment for the integrated fusion cage and graft deliverydevice, the detachable fusion cage is detachable by way of a Luer taperor Luer fitting connection, such as in a Luer-Lok® or Luer-Slip®configuration or any other Luer taper or Luer fitting connectionconfiguration. For purposes of illustration, and without wishing to beheld to any one embodiment, the following U.S. Patent Application isincorporated herein by reference in order to provide an illustrative andenabling disclosure and general description of means to selectablydetach the fusion cage of the integrated fusion cage and graft deliverydevice: U.S. Patent Appl. No. 2009/0124980 to Chen.

In another embodiment for the integrated fusion cage and graft deliverydevice, the detachable fusion cage is detachable by way of a pedicledart by threadable rotation to achieve attachment, detachment, and axialmovement. Other ways include a quick key insertion, an external snapdetent, or magnetic attraction or any other structure. For purposes ofillustration, and without wishing to be held to any one embodiment, thefollowing U.S. Patent Application is incorporated herein by reference inorder to provide an illustrative and enabling disclosure and generaldescription of means to selectably detach the fusion cage of theintegrated fusion cage and graft delivery device: U.S. Patent Appl. No.2009/0187194 to Hamada.

In another embodiment for the integrated fusion cage and graft deliverydevice, the detachable fusion cage is detachable by use of magnetism.More specifically, the detachable fusion cage can be made to feature amagnetic field pattern and a resulting force R that are adjustable andmay be of different character than the rest of the integrated fusioncage and graft delivery device. With permanent magnets, such adjustmentscan be made mechanically by orienting various permanent magnet polargeometries and corresponding shapes relative to one another. U.S. Pat.No. 5,595,563 to Moisdon describes further background regarding suchadjustment techniques, which is hereby incorporated by reference in itsentirety. Alternatively or additionally, electromagnets could be used incombination with permanent magnets to provide adjustability. In furtherembodiments, the magnets and corresponding fields and the resultantmagnetic field pattern can include both attraction forces from placementof opposite pole types in proximity to one another and repulsion forcesfrom placement of like pole types in proximity to one another. As usedherein, “repulsive magnetic force” or “repulsive force” refers to aforce resulting from the placement of like magnetic poles in proximityto one another either with or without attractive forces also beingpresent due to opposite magnetic poles being placed in proximity to oneanother, and further refers to any one of such forces when multipleinstances are present. U.S. Pat. No. 6,387,096 is cited as a source ofadditional information concerning repulsive forces that are providedtogether with attractive magnetic forces, which is hereby incorporatedby reference. In another alternative embodiment example, one or more ofsurfaces of the fusion cage are roughened or otherwise includebone-engaging structures to secure purchase with vertebral surfaces. Inyet other embodiments, the selectable detachable feature between thedetachable fusion cage and the integrated fusion cage and graft deliverydevice can include one or more tethers, cables, braids, wires, cords,bands, filaments, fibers, and/or sheets; a nonfabric tube comprised ofan organic polymer, metal, and/or composite; an accordion or bellowstube type that may or may not include a fabric, filamentous, fibrous,and/or woven structure; a combination of these, or such differentarrangement as would occur to one skilled in the art. Alternatively oradditionally, the selectable detachable feature between the detachablefusion cage and the integrated fusion cage and graft delivery device canbe arranged to present one or more openings between members or portions,where such openings extend between end portions of the fusion cage. Forpurposes of illustration, and without wishing to be held to any oneembodiment, the following U.S. Patent Application is incorporated hereinby reference in order to provide an illustrative and enabling disclosureand general description of means to selectably detach the fusion cage ofthe integrated fusion cage and graft delivery device: U.S. Patent Appl.No. 2011/0015748 to Molz et al.

In another embodiment for the integrated fusion cage and graft deliverydevice, the detachable fusion cage is detachable by use of plasmatreatment. The term “plasma” in this context is an ionized gascontaining excited species such as ions, radicals, electrons andphotons. (Lunk and Schmid, Contrib. Plasma Phys., 28: 275 (1998)). Theterm “plasma treatment” refers to a protocol in which a surface ismodified using a plasma generated from process gases including, but notlimited to, O₂, He, N₂, Ar and N₂O. To excite the plasma, energy isapplied to the system through electrodes. This power may be alternatingcurrent (AC), direct current (DC), radiofrequency (RF), or microwavefrequency (MW). The plasma may be generated in a vacuum or atatmospheric pressure. The plasma can also be used to deposit polymeric,ceramic or metallic thin films onto surfaces (Ratner, Ultrathin Films(by Plasma deposition), 11 Polymeric Materials Encyclopedia 8444-8451,(1996)). Plasma treatment is an effective method to uniformly alter thesurface properties of substrates having different or unique size, shapeand geometry including but not limited to bone and bone compositematerials. Plasma Treatment may be employed to effect magneticproperties on elements of the integrated fusion cage and graft deliverydevice, or to provide selectable detachment of the fusion cage. Forpurposes of illustration, and without wishing to be held to any oneembodiment, the following U.S. Patent Application is incorporated hereinby reference in order to provide an illustrative and enabling disclosureand general description of means to selectably detach the fusion cage ofthe integrated fusion cage and graft delivery device: U.S. Pat. No.7,749,555 to Zanella et al.

One having skill in the art will appreciate that the fusion cage may beselectably detachable to the integrated fusion cage and graft deliverydevice, for example, by means that mechanically grasp the head, meansthat attach by vacuum, and means that attach by friction, or other meansknown to those of skill in the art for attaching the head of anapparatus to the shaft of an apparatus.

It is another aspect of the present disclosure that the distal end ofthe integrated fusion cage and graft delivery device be equipped withvarious other tools to aid in the procedure. Such tools may include, forexample, devices used to assess the condition of the implantation siteand surrounding tissue. This may include, for example, a device thattransmits or provides an image or signal which carries an image forvisual inspection and photography. Such an image capture device mayinclude, for example, a device to illuminate the implant site coupledwith an image capture and/or transmission device. Another tool may alsoinclude, for example, a device that aids in irrigation or drainage ofthe surgical site, a tool used to sample or biopsy tissue.

Another embodiment for the integrated fusion cage and graft deliverydevice comprises a hollow tube constructed to receive bone graft, wherethe hollow tube has a proximal and distal end, a plunger adapted forinsertion at least partially within the hollow tube at the proximal endof the hollow tube, whereby the plunger is constructed and arranged withrespect to the hollow tube so as to prevent rotation of the plungerduring insertion into said hollow tube, whereby the plunger has a distalend that is contoured to an interior surface of the distal end of thehollow tube such that the contoured distal end of the plunger is nearlycongruent with the interior surface of the distal end of the hollow tubefor removing substantially all of the bone graft received by the hollowtube and whereby the bone graft is delivered to the graft receivingarea. Still another embodiment provides a rifling structure in thehollow tube interior that facilitates rotational movement of the plunderalong a lengthwise axis of the hollow tube, therein delivering asubstantially steady pressure and/or rate of delivery of the bone graftmaterial as the plunger descends the hollow tube when the plunger isforced through the hollow tube. The rifling or screw-like movement mayalso translate to a predetermined delivery of material per fullrotation, e.g. each 360 degree rotation of the plunger equates to 5 ccof bone graft material delivered to the bone graft site.

Another aspect of the present invention includes providing a hollow tubeand plunger assembly, in which the hollow tube and/or the plungerassembly are disposable. The tube may also be at least portions ofbiocompatible material which can stay in the canal without impairing thefinal implantation. Alternatively, it may thus be a material that isresorbable, such as a resorbable polymer, in the canal afterimplantation, so as not to interfere with the growth of the bone orstability of the implant.

A further embodiment of the invention provides pre-packaged inserts forloading into the hollow tube element, or if there are a plurality ofhollow tube elements, into one or more of the hollow tube elements. Thepre-packaged inserts may be of varying lengths, and/or layered ofdiffering materials or components, to include the patient's own bonegraft matter.

Another embodiment of the present invention provides an integratedfusion cage and graft delivery system, by which a hollow tube and/or ahollow tube/plunger assembly can be prepared prior to opening a patient,thus minimizing the overall impact of the grafting aspect of a surgicalimplantation or other procedure. Moreover, the hollow tube may be madeto be stored with bone graft in it for a period of time, whether thetube is made of plastic, metal or any other material. Depending upon thesurgical application, it may be desirable to only partially fill thetube for storage, so that a plunger can be at least partially insertedat the time of a surgery.

A further embodiment of the present invention provides a bone graftinsertion apparatus comprising a hollow tube constructed to receive bonegraft, the hollow tube having a proximal and distal end whereby thehollow tube contains least one opening on a surface of the distal end ofthe hollow tube. The at least one opening is preferably positioned otherthan completely along the axial or longitudinal axis of the device. Thenumber and size and shape of such openings can vary but are preferablyadapted to deliver bone graft material in a direction substantiallytransverse to the axial extent of the substantially hollow tube. In oneembodiment, two or more apertures are provided. In certain embodiments,apertures are on the same side of the hollow tube, where in others,apertures are on different sides (e.g. opposing sides) of a hollow tube.A plunger, adapted for insertion at least partially within the hollowtube, is constructed and arranged with respect to the hollow tube so asto present at least one substantially flat contour, whereby the plungerhas a distal end that is contoured to an interior surface of the distalend of the hollow tube such that the contoured distal end of the plungeris nearly congruent with the interior surface of the distal end of thehollow tube. This facilitates removing substantially all of the bonegraft received by the hollow tube whereby the bone graft is delivered tothe graft receiving area. It is important to remove substantially all ofthe bone graft material as it is expensive and/or difficult to obtain.

In another embodiment of the present disclosure the distal end of theplunger is flexible to allow, for example, the user to maneuver thedistal end and thereby any bone graft material in the hollow tube to theimplantation site. One skilled in the art will appreciate that theflexible aspect of certain embodiments can be both passive and active innature. Active flexibility and manipulation in the distal end of theplunger may incorporate, for example, the manipulative capabilities ofan endoscope, including components for manipulation such as guidewiresalong the longitudinal axis of the shaft of the plunger.

In another embodiment of the invention, the distal end and the proximalend of the hollow tube are in communication via a conduit to enableelectrical, hydraulic, pneumatic, or mechanical transmission, the latersuch as a wire. Such hydraulic communication allows, for example, amedical or other liquid to be delivered or extracted from the surgicalarea. Such mechanical communication allows, for example, the distal endto be maneuvered precisely.

In another embodiment of the present disclosure, the hollow tube and/orplunger may be curved and/or may have an angular aspect, in addition tothe sloped or curved surface at a second end of the hollow tube/plunger.This shape may, for example, aid the surgeon in more comfortablyintroducing the delivery device to the implant site, be shaped to betteraccommodate implantation sites on right or left sides of the body, or beshaped to better accommodate right or left-handed surgeons. One havingskill in the art will appreciate that the delivery device may havemultiple angles and curved aspects which enable aspects of embodimentsof the present disclosure or aid in ergonomics.

In one embodiment of the present disclosure, the device furthercomprises a footing or shelf at the distal end of the tubular devicethat is nearest the operating site for preventing or mitigating risk ofinjury to the patient during surgery. According to this embodiment, thefooting may be flexible, semi-flexible, semi-rigid or rigid. The footingserves to protect the anatomy of the patient from being penetrated bythe hollow tube of the integrated fusion cage and graft delivery devicewhen the plunger is being inserted or during tamping of the hollow tubeor the plunger by the surgeon, which may occur during the surgicalprocedure for a variety of reasons. In certain embodiments, the distaltip region of the hollow tube comprises a softer, maliable and/or lessrigid material than the remainder of the hollow tube. For example, thedistal tip could be made of a bioactive collagen.

It is yet another aspect of the present disclosure to provide anintegrated fusion cage and graft delivery device that contains one ormore detachable elements for use in an operation where bone graftmaterial must be inserted into the integrated fusion cage and graftdelivery device and ejected to a bone graft receiving area. According tovarious embodiments, these detachable devices may include a detachablefunnel for gathering and inserting bone graft material at a graspableend of the integrated fusion cage and graft delivery device. The presentdisclosure may also comprise a plunger that has a detachable handle,which may be selectively removed to avoid blocking the surgeon's view ofthe operating site. The integrated fusion cage and graft delivery devicemay further comprise a detachable footing or shelf at one distal end ofthe hollow tubular member. In one embodiment this footing or shelf isselectively positionable about various points along the hollow tube. Forexample, a distal portion of the hollow tube has a rotatable portionthat can be positioned to deliver bone graft material to areas of a discspace in a manner such that a surgeon has angular directional control asto where bone graft material is directed. Other detachable elements arealso contemplated with the present invention, such as a funnel at theproximal end of the hollow tube, or exterior or interior guide wiresattached to the hollow tube, or a camera which is positioned near thedelivery site of the bone graft material.

In another embodiment of the invention, the device is configured suchthat the upper or first end of the device (that is, the end in which theplunger is inserted) is not substantially in-line with the second end ofthe device (that is, the end from which bone graft material is emittedand/or a fusion cage is attached). For example, the body of the hollowtube may be configured with an angle or kink along its length, appearingto be rotated along its length. In this embodiment, the plunger elementis flexible and/or conformable so as to flex inside of the tube portionand otherwise traverse through the tube portion. This embodiment of thedevice is useful, for example, when the user requires entry to the discspace at other than a right angle. Further, the angle or kink along thelength of the device may be configured is capable of selectively locking(e.g., by a pin) the upper device portion into a particular position,e.g. so that a desired angle is created between the upper device portionand the remaining portion of the device. The means for communicationitself can be locked to alternatively achieve this objective. In oneembodiment, when the rotating member is in an unlocked mode, the memberis free to rotate in at least one plane. The selective locking mechanismcan be remotely accessed by a user of the tool at the upper end of thehandle by, for example, an external shaft that communicates with thelocking mechanism of the rotating member on the distal end of the body.Yet another aspect of the present disclosure is that the device can bevariably angled to allow for a variety of insertion angles. A ratchetingadapter can be fitted to allow for this application.

The present invention can be used in veterinary conditions, in thethoracic spine or can be used for insertion of a laterally based diskreplacement.

Thus, according to various embodiments of the present disclosure, amethod of introducing bone graft material to a desired operating site(“bone graft receiving area”) is provided by use of a hollow tubularmember comprising a generally rectangular cross-sectional area, wherebythe desired operating area is capable of receiving at least one plunger.The one or more plunger having at least one distal end which is designedto accommodate ejecting bone graft or other material to be inserted intothe joint space or between intervertebral members in a generally lateraldirection, as opposed to a generally longitudinal direction (in relationto the direction of the primary axis of the device).

One skilled in the art will appreciate that the distal end of thetubular device need not be limited to those specific embodimentsdescribed above. Other forms, shapes or designs that enable theforegoing aspects of the present invention are hereby incorporated intothis disclosure. Forms, shapes and designs that relate to the provisionof an end of a tubular device to perform lateral introduction of bone orbone substitute to an operating site are considered to be within thescope of the present disclosure.

One aspect of the present invention provides an integrated fusion cageand graft delivery device system for delivering bone graft, in apartially formed, fully formed or unformed condition to a bone graftreceiving area in a body.

In yet another embodiment the hollow tube of the integrated fusion cageand graft delivery device may further comprise a funnel on the graspableend of the hollow tube, which may be selectively positioned about thegraspable end of the hollow tube, for facilitating insertion of new oradditional bone graft into the hollow tube. The funnel may take on avariety of shapes and sizes, depending on the nature of the bone graftmaterial being inserted in the hollow tube.

One embodiment of the substantially hollow tube provides that the hollowtube is telescoping, thereby allowing its length to be adapted to theparticular desires of the surgeon and/or the surgical area. In thisembodiment, the plunger may also be telescoping to substantially conformto the configuration and/or size and/or shape of the substantiallyhollow tube.

In another embodiment, the size and/or shape of the one or more hollowtubes of the device are sized to fit, and/or not substantially obscureaccess to the aperture of, the cannula or cannulas that the device isfitted through for delivery of bone graft material to the operatingsite. In this embodiment, the device's one or more pair of hollow tubesand plungers do not substantially impair access to the operating sitenor the surgeon's view of the operating site.

In one embodiment of the invention, a bone graft insertion apparatuscomprises: a hollow tube constructed to receive bone graft, said hollowtube having an extended axis and a proximal end and a distal end, saiddistal end having an interior surface; a plunger adapted for insertinginto said proximal end of said hollow tube, said plunger having a distalend being contoured to said interior surface of said distal end of saidhollow tube such that bone graft material within said hollow tube isdelivered to a graft receiving area through at least one opening nearthe distal end of said hollow tube; wherein said graft receiving area isconfigured to accommodate at least one substantially hollow implant.

In another embodiment of the invention, a bone graft insertion apparatuscomprises: a hollow tube constructed to receive bone graft, said hollowtube having a proximal and distal end; whereby said hollow tube containsleast one opening on a surface of said distal end of said hollow tube;whereby said opening on a surface of said distal end of said hollow tubeis positioned other than completely along the axial or longitudinal axisof the device; a plunger adapted for insertion at least partially withinsaid hollow tube at proximal end of said hollow tube; whereby saidplunger is constructed and arranged with respect to said hollow tube soas to present at least one substantially flat contour; whereby saidplunger has a distal end that is contoured to an interior surface ofsaid distal end of said hollow tube such that said contoured distal endof said plunger is nearly congruent with said interior surface of saiddistal end of said hollow tube for removing substantially all of saidbone graft received by said hollow tube; whereby said bone graft isdelivered to a graft receiving area.

In another embodiment of the invention, a method of inserting bone graftcomprises: preparing a surgical area to receive bone graft; inserting atool into said surgical area, said tool consisting essentially of ahollow tube adapted to receive bone graft, a plunger adapted forinsertion into said hollow tube, said plunger constructed to preventrotation during insertion into said hollow tube, said plunger having adistal end contoured to the interior surface of the distal end of saidhollow tube; providing bone graft material into the said hollow tube ofsaid tool; inserting said plunger into the proximal end of said hollowtube; inserting said distal end of said hollow tube of said tool intosurgical area; applying force to said plunger thereby advancing saidplunger through said hollow tube wherein said bone graft is insertedinto said surgical area.

In another embodiment of the invention, an integrated fusion cage andgraft delivery device apparatus comprises: a hollow tube constructed toreceive bone graft, the hollow tube having an extended axis and aproximal end and a distal end, the distal end having an interiorsurface; a plunger adapted for inserting into the proximal end of thehollow tube, the plunger having a distal end being contoured to theinterior surface of the distal end of the hollow tube; a selectablydetachable fusion cage, the selectably detachable fusion cage having atleast one opening that substantially aligns with at least one openingnear the distal end of the hollow tube, such that bone graft materialwithin the hollow tube is delivered to a graft receiving area through atleast one opening of the selectably detachable fusion cage; and theselectably detachable fusion cage having a means for detachment wherebythe fusion cage is delivered to the graft receiving area.

In one embodiment, the device is not a caulking gun style device, thatis the bone graft material and/or the fusion cage are not deliveredand/or positioned using a hand-pump and/or hand-squeeze mechanism.Instead, the device delivers graft material and/or a fusion cage using ahollow tube and plunger arrangement which is not a caulking gun styledevice and further, does not appreciably disrupt or block the user'sview of the surgical site and/or enable precision delivery of bone graftmaterial and/or a fusion cage to the surgical site. Indeed, the deviceis distinctly unlike the chalking gun device of U.S. Pat. Appl. No.2004/0215201 to Lieberman (“Lieberman”), which requires an L-shaped basemember handle, rack teeth to advance a plunger member, and user actionon a lever of the L-shaped base member handle to deploy bone graftmaterial. In one embodiment, the device of this application is not acaulking gun style device and does not comprise rack teeth, a basemember handle and at least one component that obscures user viewing ofthe surgical site. Lieberman is incorporated by reference in itsentirety for all purposes.

Similarly, in one embodiment, the device is distinctly unlike thechalking gun device of U.S. Pat. Appl. No. 2002/0049448 to Sand et al(“Sand”), which requires a gun and trigger mechanism in which the usersqueezes together a gun-style handle to deploy material into bone. TheSand device obstructs the view of the user of the delivery site. In oneembodiment, the device of this application is not a caulking gun styledevice and does not comprise an opposing-levered, gun-style deliverymechanism and at least one component that obscures user viewing of thesurgical site. Sand is incorporated by reference in its entirety for allpurposes.

In one embodiment, the device is configured to deliver bone graftmaterial substantially laterally from its delivery end, that issubstantially not in the axial direction but rather substantially fromthe side and/or in a radial direction. This is distinctly different thandevices that deliver bone graft material along their vertical axis, thatis, along or out their bottom end, and/or obstruct the user view of thebone graft and/or fusion cage delivery site, such as that of U.S. Pat.Appl. No. 2010/0087828 to Krueger et al (“Krueger”), U.S. Pat. Appl. No.2009/0264892 to Beyar et al (“Beyar”), U.S. Pat. Appl. No. 2007/0185496to Beckman et al (“Beckman”), U.S. Pat. Appl. No. 2009/0275995 toTruckai et al (“Truckai”) and U.S. Pat. Appl. No. 2006/0264964 toScifert et al (“Scifert”). Krueger, Beyar, Beckman, Truckai and Scifertare incorporated by reference in their entireties for all purposes.

In one embodiment, the device is configured to deliver bone graftmaterial so as to completely fill the defined interior of its fusioncage and subsequently deliver bone graft material to the surroundingbone graft site, rather than, for example, to contain the bone materialas are the fusion cage designs of U.S. Pat. No. 7,846,210 to Perez-Cruet(“Perez-Cruet”). Further, the fusion device of this application featuresa distal tip that functions to precisely position the fusion device andstabilize the device during delivery of bone graft material. Perez-Cruetis incorporated by reference in its entirety for all purposes.

In one embodiment, a bone graft insertion apparatus is disclosed, thebone graft insertion apparatus comprising: a hollow tube constructed toreceive bone graft, said hollow tube having an extended axis and aproximal end and a distal end, said distal end having a substantiallytapered distal tip interior surface and a distal end interior surface ofrectangular cross-section; a plunger adapted for inserting into saidproximal end of said hollow tube, said plunger having a distal endexterior surface of rectangular cross-section contoured to said distalend interior surface of said hollow tube, said plunger having asubstantially tapered distal tip contoured to said substantially tapereddistal tip interior surface of said hollow tube to form a substantiallycongruent fit, wherein bone graft material within said hollow tube isdelivered to a graft receiving area through one or more lateral openingsnear said distal end of said hollow tube, said one or more lateralopenings substantially precluding the delivery of bone graft materialdirectly along said axis of said hollow tube, said plunger precludedfrom rotating when inserted into said hollow tube.

In another embodiment, a bone graft insertion apparatus is disclosed,the bone graft insertion apparatus comprising: a hollow tube having alength, a proximal end and a distal end, said hollow tube having arectangular cross-section, said distal end having a tapered tip interiorsurface and at least one opening; a plunger adapted for insertion withinsaid hollow tube at said proximal end of said hollow tube, said plungerhaving a rectangular cross-section end portion and a distal tipcontoured to conform to the distal end of said hollow tube, said plungerhaving a length sufficient such that when fully inserted into saidhollow tube, said plunger distal end contacts at least one opening.

In another embodiment, a bone graft insertion apparatus is disclosed,the bone graft insertion apparatus comprising: a hollow tube constructedto receive bone graft having an extended axis, a length, a proximal endand a distal end, said hollow tube having a rectangular cross-section,said distal end having a tapered tip interior surface with a terminusand two oval-shaped openings having an upper and a lower end located onopposite lateral sides of said distal end, said tapered tip extendinginto said hollow tube and said terminus positioned adjacent to saidoval-shaped openings; a plunger adapted for insertion within said hollowtube at said proximal end of said hollow tube, said plunger having arectangular cross-section end portion and a distal lower surface, saidplunger having a length sufficient such that when fully inserted intosaid hollow tube, said plunger distal lower surface contacts said hollowtube terminus at a position adjacent to said oval-shaped openings, saidplunger rectangular cross-section end portion forming a continuoussurface adjacent each of the oval-shaped openings from a positionopposite said terminus to a point extending beyond said upper end ofeach oval-shaped opening; wherein bone graft material within said hollowtube is delivered to a graft receiving area through said oval-shapedopenings of said hollow tube, said oval-shaped openings precluding thedelivery of bone graft material directly along said axis of said hollowtube, said plunger precluded from rotating when inserted into saidhollow tube; wherein said oval-shaped openings near the distal end ofsaid hollow tube are positioned within a 25% length from said distal endrelative to a total length of said hollow tube.

One of ordinary skill in the art will appreciate that embodiments of thepresent disclosure may have various sizes. The sizes of the variouselements of embodiments of the present disclosure may be sized based onvarious factors including, for example, the anatomy of the implantpatient, the person or other device operating the apparatus, the implantlocation, physical features of the implant including, for example, with,length and thickness, and the size of operating site or the size of thesurgical tools being used with the device.

One or ordinary skill in the art will appreciate that embodiments of thepresent disclosure may be constructed of materials known to provide, orpredictably manufactured to provide the various aspects of the presentdisclosure. These materials may include, for example, stainless steel,titanium alloy, aluminum alloy, chromium alloy, and other metals ormetal alloys. These materials may also include, for example, PEEK,carbon fiber, ABS plastic, polyurethane, rubber, latex, syntheticrubber, and other fiber-encased resinous materials, synthetic materials,polymers, and natural materials. The plunger element could be flexible,semi-rigid, or rigid and made of materials such as stainless steel,titanium alloy, aluminum alloy, chromium alloy, and other metals ormetal alloys. Similarly, the tubular element could be flexible,semi-rigid, or rigid and made of materials such as stainless steel,titanium alloy, aluminum alloy, chromium alloy, and other metals ormetal alloys. In certain embodiments, the plunger and hollow tube arecomposed of plastic and are intended for one use only and thendiscarded. In another embodiment, some or all elements of the device, orportions of some or all of the elements, are luminescent. Also, inanother embodiment, some or all elements of the device, or portions ofsome or all of the elements, include lighting elements. In anotherembodiment, the hollow tube and/or plunger are made of a substantiallytransparent material and/or are rigidly opaque.

In one embodiment of the fusion cage, the fusion cage comprises apolymer, such as PEEK, titanium and composite materials.

One of ordinary skill in the art will appreciate that embodiments of thepresent disclosure may be controlled by means other than manualmanipulation. Embodiments of the present disclosure may be designed andshaped such that the apparatus may be controlled, for example, remotelyby an operator, remotely by an operator through a computer controller,by an operator using proportioning devices, programmatically by acomputer controller, by servo-controlled mechanisms, byhydraulically-driven mechanisms, by pneumatically-driven mechanisms orby piezoelectric actuators.

Embodiments of the present disclosure present several advantages overthe prior art including, for example, the speed of the procedure, theminimally invasive aspect of the procedure, the ability to introduce theimplant material to the implant site with minimal risk and damage to thesurrounding tissue, the lower risk of infection, more optimally placedimplant material, a more stable delivery device which is designed toreduce the likelihood of the implant material becoming dislodged priorto fixation, and fewer tools in a surgical site due to the integrationof several components required to provide bone graft to a bone graftreceiving area. Further, the lower profile of the device allows improvedviewing of the area intended for receipt of bone graft material, and useof a reduced set and size of elements therein provided a less expensivedevice. Also, the device disclosed provides that substantially all ofthe bone graft material may be ejected from the device and delivered tothe surgical site, rather than wasted as unretrievable matter remaininginside the device. The ability to remove substantially all of the bonegraft material is of significant benefit because the bone graft materialis expensive and/or hard to obtain.

This Summary of the Invention is neither intended nor should it beconstrued as being representative of the full extent and scope of thepresent disclosure. The present disclosure is set forth in variouslevels of detail in the Summary of the Invention as well as in theattached drawings and the Detailed Description of the Invention, and nolimitation as to the scope of the present disclosure is intended byeither the inclusion or non-inclusion of elements, components, etc. inthis Summary of the Invention. Additional aspects of the presentdisclosure will become more readily apparent from the DetailedDescription, particularly when taken together with the drawings.

The above-described benefits, embodiments, and/or characterizations arenot necessarily complete or exhaustive, and in particular, as to thepatentable subject matter disclosed herein. Other benefits, embodiments,and/or characterizations of the present disclosure are possibleutilizing, alone or in combination, as set forth above and/or describedin the accompanying figures and/or in the description herein below.However, the Detailed Description of the Invention, the drawing figures,and the exemplary claim set forth herein, taken in conjunction with thisSummary of the Invention, define the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the disclosure andtogether with the general description of the disclosure given above andthe detailed description of the drawings given below, serve to explainthe principles of the disclosures.

It should be understood that the drawings are not necessarily to scale.In certain instances, details that are not necessary for anunderstanding of the disclosure or that render other details difficultto perceive may have been omitted. It should be understood, of course,that the disclosure is not necessarily limited to the particularembodiments illustrated herein.

FIG. 1A is a front perspective view of the device for delivering bonegraft;

FIG. 1B is a front perspective view of the plunger of the device;

FIG. 1C is a cross sectional view of a portion of the device shown inFIG. 1A;

FIG. 2 is another front perspective view of the device of FIGS. 1A and1B, showing the relationship between the tubular and plunger portions ofthe device;

FIG. 3 is a front perspective view of the device according to onealternative embodiment where the tubular portion includes a foot sectionand where the plunger portion has been fully inserted into the tubularportion;

FIG. 4 is a partial front perspective view of another alternativeembodiment of the device where the tubular portion includes a funnel atits proximal end designed to receive bone graft;

FIG. 5 is a partial front perspective view of the device according toone embodiment where the device is positioned in a disc space during asurgical operation;

FIG. 6 is a front perspective view of one embodiment of the device,showing the relationship between the tubular and plunger portions wherethe tubular portion includes two lateral facing openings at the distalend of the tubular portion and a wedge-shaped distal end of the tubularmember;

FIG. 7 is another front perspective view of the tubular portion of thedevice of FIG. 6 showing the second of two lateral openings at thedistal end of the tubular portion and a wedge-shaped distal end of thetubular member;

FIG. 8 is a front elevation view of the distal end of the tubularportion of the device of FIG. 6;

FIG. 9 is a bottom elevation view of the proximal end of the tubulardevice of FIG. 6;

FIG. 10A is a top plan view of the device of FIG. 6 with the plungerportion fully inserted into the tubular portion;

FIG. 10B is a left elevation view of the device of FIG. 6 with theplunger portion fully inserted into the tubular portion;

FIG. 10C is a bottom plan view of the device of FIG. 6 with the plungerportion fully inserted into the tubular portion;

FIG. 10D is a right elevation view of the device of FIG. 6 with theplunger portion fully inserted into the tubular portion;

FIG. 11A is a front perspective view of one embodiment of the fusioncage of the device, showing a tapered proximal end and medial openings;

FIG. 11B is a top plan view of the fusion cage of FIG. 11A;

FIG. 11C is a left elevation view of the fusion cage of FIG. 11A;

FIG. 11D is a rear elevation view of the fusion cage of FIG. 11A;

FIG. 12A is a front perspective view of another embodiment of the fusioncage of the device;

FIG. 12B is a front perspective view of yet another embodiment of thefusion cage of the device;

FIG. 12C is a front perspective view of yet another embodiment of thefusion cage of the device;

FIG. 13 is a front perspective view of one embodiment of the device,showing the relationship between the tubular and plunger portions wherethe tubular portion includes two lateral facing openings at the distalend of the tubular portion and a wedge-shaped distal end of the tubularmember, and a fusion cage fitting over the exterior distal end of thetubular member;

FIG. 14A is a top plan view of the device of FIG. 13 with the plungerportion fully inserted into the tubular portion and the fusion cagefully inserted over the tubular portion;

FIG. 14B is a left elevation view of the device of FIG. 13 with theplunger portion fully inserted into the tubular portion and the fusioncage fully inserted over the tubular portion;

FIG. 14C is a bottom plan view of the device of FIG. 13 with the plungerportion fully inserted into the tubular portion and the fusion cagefully inserted over the tubular portion;

FIG. 14D is a right elevation view of the device of FIG. 13 with theplunger portion fully inserted into the tubular portion and the fusioncage fully inserted over the tubular portion;

FIG. 15A is a front perspective view of another embodiment of the fusioncage of the device;

FIG. 15B is a top plan view of another embodiment of the device whereinthe fusion cage of the device includes internal ramps and locking slotsconfigured to engage locking tabs of the tubular portion, and theplunger includes a tapered tip;

FIG. 15C is a left elevation view of the fusion cage of FIG. 15B;

FIG. 15D is a front elevation view of the tubular portion of FIG. 15B;

FIG. 16 is a top plan view of another embodiment of the device with theplunger portion partial inserted into the tubular portion and the fusioncage engaged with the tubular portion via a break-off collar;

FIG. 17A is a top plan view of another embodiment of the device whereinthe fusion cage engages with a connector conduit which in turn engageswith the tubular portion;

FIG. 17B is a cross-sectional view of section A-A of FIG. 17A;

FIG. 18A is a top plan view of another embodiment of the device whereinthe tubular portion comprises a telescoping feature;

FIG. 18B is a left elevation view of the device of FIG. 18A;

FIG. 18C is a bottom plan view of the device of FIG. 18A;

FIG. 18D is a right elevation view of the device of FIG. 18A;

FIG. 19A is a top plan view of a fusion cage of an embodiment of thedevice particularly adapted for use in anterior lumbar interbody fusionprocedures;

FIG. 19B is a front elevation view of the device of FIG. 19A;

FIG. 19C is a left elevation view of the device of FIG. 19A;

FIG. 19D is a view of the device of FIG. 19A inserted between vertebrae;

FIG. 20A is a cross-sectional top plan view of a fusion cage of anembodiment of the device particularly adapted for use in direct lateralinterbody fusion procedures;

FIG. 20B is a front elevation view of the device of FIG. 20A;

FIG. 20C is a left elevation view of the device of FIG. 20A;

FIG. 20D is a view of the device of FIG. 20A inserted between vertebrae;

FIG. 21A is a front perspective view of a fusion cage of an embodimentof the device particularly adapted for use in connection withvertebrectomy procedures;

FIG. 21B is a left perspective view of the device of FIG. 21A;

FIG. 21C is a front elevation view of the device of FIG. 21A insertedinto a surgical site;

FIG. 21D is a left elevation view of the device of FIG. 21A insertedinto a surgical site;

FIG. 22 is a front perspective view of another embodiment of the devicefor delivering bone graft;

FIG. 23 is a front perspective exploded view of the device shown in FIG.22;

FIG. 24 is a top plan view of the device shown in FIG. 22;

FIG. 25 is a front elevation view of the device shown in FIG. 22;

FIG. 26 is a right elevation view of the device shown in FIG. 22;

FIG. 27 is a bottom plan view of the device shown in FIG. 22;

FIG. 28 is a cross-sectional view of section A-A of FIG. 25;

FIG. 29 is a front elevation view of the plunger element of the deviceshown in FIG. 22;

FIG. 30 is a cross-sectional view of section B-B of FIG. 29;

FIG. 31 is a cross-sectional of section C-C of FIG. 29;

FIG. 32 is a detailed front perspective view of a portion of the deviceshown in FIG. 22;

FIG. 33 is a cross-sectional view of section D-D of FIG. 32;

FIG. 34A is a bar graph describing experimental results of bone graftdelivery and disk material removed for L4-5;

FIG. 34B is a bar graph describing experimental results of bone graftdelivery and disk material removed for L5-S1;

FIG. 35A is a table describing experimental results of bone graftdelivery and disk material removed; and

FIG. 35B is a graph of the table of FIG. 35A describing experimentalresults of bone graft delivery and disk material removed.

DETAILED DESCRIPTION

The present invention relates to a device and method for integrated andnear-simultaneous delivery of bone graft material and a fusion cage toany portion of a patient which requires bone graft material and/or afusion cage. Thus, for example, the foregoing description of the variousembodiments contemplates delivery to, for example, a window cut in abone, where access to such window for bone grafting is difficult toobtain because of orientation of such window, presence of muscle tissue,risk of injury or infection, etc. The integrated fusion cage and graftdelivery device is formed such that the one or more hollow tubes and/orplungers may be helpful in selectively and controllably placing bonegraft material and a fusion cage in or adjacent to such window. Theintegrated fusion cage and graft delivery device is formed to allowdelivery of bone graft material and/or a fusion cage in a directionother than solely along the longitudinal axis of the device, and in someembodiments transverse to the primary axis used by the surgeon oroperator of the device when inserting the device into a cannula or otherconduit to access the surgical site. This same concept applies to otherareas of a patient, whether or not a window has been cut in a bone, forexample in a vertebral disc space, and may be used whether this is afirst surgery to the area or a follow-up surgery. The present inventionalso contemplates the delivery of bone graft material and/or a fusioncage with or without the use of a plunger, and with or without the useof various other tools described in greater detail herein.

Referring now to FIGS. 1-33, several embodiments of the presentinvention are shown.

In regard to FIG. 1A, an integrated fusion cage and graft deliverydevice portion is shown, which is comprised of a hollow tubular memberor hollow tube or contains at least one inner lumen 2, which has a firstproximate end 6 (which is referred to elsewhere in this specification asthe “graspable end” of hollow tube 2), and a second distal end 8, with ageneral hollow structure therebetween. Thus, as shown in FIG. 1, thehollow tube 2 allows bone graft material to be inserted into the opening4 at the graspable end 6 of the hollow tube 2, and ultimately exitedfrom the hollow tube 2 through the second end 8. According to apreferred embodiment, the hollow tube 2 also comprises at least onesloped or curved surface 10 at or near the second end 8 of the hollowtube 2. Although a generally rectangular cross-section is depicted, thecross-section need not be limited to a generally rectangular shape. Forexample, cross-sections of an oval shape or those with at least onedefined angle to include obtruse, acute, and right angles can provide ashape in some situations that is more congruent with the size or shapeof the annulotomy of a particular disc space.

Referring now in detail to FIG. 1B, a plunger 12 is shown for use withthe hollow tube 2 of FIG. 1A. The plunger 12 is generally of the samegeometry as the hollow portion of the hollow tube 2, extending at leastthe same length of hollow tube 2. The plunger 12 may includes, asdepicted in FIG. 1B at least one knob or handle 16 for grasping by auser of the plunger 12. As with the interior of the hollow tube 2 at itssecond end 8, the plunger 12 also comprises at least one sloped orcurved surface 20 at or adjacent to a second end 18 of the plunger 12.The plunger 12 terminates in a generally flat, horizontal surface 19,which corresponds to the opening at the second end 8 of the hollow tube2 shown in FIG. 1A. Thus, in cooperation, the plunger 12 may be insertedinto the opening 4 of the hollow tube 2 shown in FIG. 1A, and extendedthe entire length of the hollow tube 2, at least to a point where thehorizontal surface 19 of plunger 12 is in communication with the secondend 8 of the hollow tube 2. This configuration permits a user to ejectsubstantially all of the bone graft material that is placed into thehollow tube 2 during a surgical procedure. One skilled in the art willappreciate that the plunger need not terminate in a generally flat,horizontal surface to effect the substantial removal of all of the bonegraft material placed into the hollow tube; more specifically, any shapethat allows conformance between the internal contour of the distal endof the hollow tube and the distal end of the plunger will effect thesubstantial removal of the bone graft material. Further details aboutthe relationship are described below in regard to FIG. 2.

In the embodiment, of FIG. 1A-C, a contoured leading edge is provided onthe plunger to correspond with the internal contour of distal end of thehollow tube of the delivery device. This contoured plunger servesseveral purposes: First, it maintains the plunger in a desirablerotational position with respect to the hollow tube (i.e., prevents theplunger from inadvertently or intentionally being manipulated to rotateabout the longitudinal axis of the hollow tube). Second, it ensure thatwhen the plunger is fully inserted, the plunger removes substantiallyall of the bone graft material from the hollow tube. Also, the contouredplunger, corresponding to the contoured tubular member, allows immediateidentification of the orientation of the device, and more specificallythe direction of eject of the bone graft material into the surgicalarea. Alternative positioning means may also be provided to ensure thatthe plunger remains in the desirable position during delivery of bonegraft into the hollow tube, for example by a machined bevel or edge onthe outer surface of the plunger, and a corresponding groove in theinterior surface of the hollow tube, which must be aligned wheninserting the plunger in the hollow tube.

Referring now to FIG. 1C, an elevation view of the hollow tube 2 shownin FIG. 1A is shown in detail. The second end 8 of the hollow tube 2 hasan opening with a height A and width B according to the needs of thesurgeon, the location of the bone graft receiving area, the nature ofthe surgical operation to be performed, and the quantity and type ofbone graft that is being inserted in (and ultimately ejected from) thisintegrated fusion cage and graft delivery device. According to apreferred embodiment, the height A of the opening at the second end 8 ofthe hollow tube 2 is in the range of 4 mm to 9 mm, and in a mostpreferred embodiment is about 7 mm. According to a preferred embodiment,the width B of the opening at the second end 8 of the hollow tube 2 isin the range of 7 mm to 14 mm, and in a most preferred embodiment isabout 10 mm.

Referring to FIGS. 1A-C, it is to be understood that although theseparticular drawings reflect an embodiment where the second end 8 of thehollow tube 2, and the second end 18 of the plunger 12 comprise a curvedor sloped surface which extends at least a certain distance laterallyaway from the generally longitudinal axis of the hollow tube 2/plunger12, that in other embodiments, the second end 8 of the hollow tube 2(and thereby, the second end 18 of the plunger 12) do not extend alateral distance away, but rather terminate along the longitudinal wallof the hollow tube 2. In this embodiment, the hollow tube 2 may have asecond end 8 which has an opening that is carved out of the side of thewall of the hollow tube 2, such that it appears as a window in thetubular body of hollow tube 2. According to this embodiment, thehorizontal face 19 of the plunger 12 would also be a face on the outersurface of plunger 12, without extending any lateral distance away fromthe body of plunger 12. According to this embodiment, the plunger 12would still retain the curved or sloped surface at the opposite end ofthe horizontal face 19 (referred to in FIG. 1B as 20) and similarly thehollow tube 2 would still comprise a sloped or curved surface 10opposite the opening at second end 8. It is to be expressly understoodthat other variations which deviate from the drawing FIGS. 1A-C are alsocontemplated with the present invention, so long as that the opening atthe second end 8 of hollow tube 2 is oriented to permit bone graft to beexited from the hollow tube 2 in a generally lateral direction (inrelation to the longitudinal direction of the axis of the hollow tube2).

According to another embodiment, the plunger 12 shown in FIG. 1B mayfurther comprise a secondary handle (not shown in FIG. 1B), whichincludes an opening about at least one end of secondary handle such thatit is permitted to couple with handle 16 of plunger 12. In this fashion,the secondary handle may be larger, contain one or more rings orapertures for placing a users hand and/or fingers, or may simply be of amore ergonomic design, for accommodating use of the plunger 12 during asurgical operation. The secondary handle, according to this embodiment,is selectively removable, which permits a surgeon to use the secondaryhandle for inserting the plunger 12, and then at a later point removethe secondary handle, for instance, to improve visibility through theincision or through the hollow tube 2, and/or to determine whethersubstantially all of the bone graft material has been ejected from thehollow tube 2.

Referring now in detail to FIG. 2, the plunger 12 is shown inserted intothe hollow tube 2, such that the horizontal face 19 is substantiallyplanar with the opening at the second end 8 of the hollow tube 2. Asdescribed above, the geometry of plunger 12 is such that it fits snugglyor tightly in the interior of the hollow tube 2. This configuration issuch that the sloped or curved surface 10 of the hollow tube 2 issubstantially congruent to the sloped or curved surface 20 (not shown inFIG. 2), thereby allowing the plunger to be inserted into the hollowtube 2 and allowing substantially all of bone graft material which isplaced into the hollow tube 2 to be ejected by the user.

Referring now in detail to FIG. 3, an alternate embodiment of thepresent invention is shown. According to this embodiment, the hollowtube 2 comprises a footing 11 at the second end 8 of the hollow tube 2.This footing 11 extends in a lateral direction, opposite the directionof the opening at the second end 8 of the hollow tube 2. The purpose ofthis footing 11 is to prevent injury to the annulus of a patient, orother sensitive anatomy adjacent the bone graft receiving area. Thisfooting 11 is helpful when a surgeon or other user of the integratedfusion cage and graft delivery device is using the plunger 12 to drivebone graft through the hollow tube 2, or using another tool, such as atamp, mallet, or other driving or impacting device to strike the plunger12 and/or hollow tube 2 during the surgical procedure. Without thefooting 11, the hollow tube 2 would have a generally angular second end8, which may cause damage to the patient during these types ofprocedures. Thus, the footing 11 prevents the second end 8 of the hollowtube 2 from penetrating the annulus or other sensitive anatomy of thepatient.

According to this embodiment, the footing 11 may also operate to ensurea fixed position of the second end 8 of the hollow tube 2 in thesurgical site. This in turn allows a user to ensure that bone graftejecting the second end 8 of the hollow tube 2 is being ejectedlaterally, and in the desired direction. This may be important, forexample, when the integrated fusion cage and graft delivery device isplaced within a disc space, and bone graft is being ejected laterallyfrom the second end 8 of the hollow tube 2 in a specific direction. Inother embodiments, the footing 11 may also serve as a visual marker forthe surgeon, as it extends away from the horizontal wall of the hollowtube 2, and is therefore visible at the second end 8 of the hollow tube2. As shown in FIG. 3, the presence of the footing 11 does not affectthe interior slope or curved surface 10A of the hollow tube 2, so thatthe plunger 12 of the design shown in FIG. 1B may still be used with thehollow tube 2 of this alternate embodiment.

Referring now in detail to FIG. 4, a removable funnel 30 is shown, whichcomprises an opening 34 which is generally larger in diameter ordimension when compared to the opening 4 of the hollow tube 2. Thisremovable funnel 30 further comprises a sleeve 32, the sleeve 32 havingan internal cross-section which is substantially congruent with theexternal cross-section of the first end 6 of the hollow tube 2. Thus,according to this embodiment, the funnel 30 is selectively removablefrom the first end 6 of the hollow tube 2, and may allow a surgeon tomore easily place new or additional bone graft into the hollow tube 2 byway of the opening 34 of the funnel 30. This funnel 30 may be used inconnection with a hollow tube 2 that has been pre-filled with bonegraft, or a hollow tube which is not pre-filled with bone graft. Thus,the funnel may be selectively positioned on the first end 6 of thehollow tube 2 at any point during the surgical operation when thesurgeon desires new or additional bone graft be placed in the hollowtube 2 of the integrated fusion cage and graft delivery device.

Referring now in detail to FIG. 5, one particular application of theintegrated fusion cage and graft delivery device is shown in aperspective view. Here, the integrated fusion cage and graft deliverydevice is shown with the embodiment of the hollow tube 2 furthercomprising a footing 11, and a second end opening for ejecting bonegraft in a generally lateral direction, here in the interior of a discspace 40. The disc is shown with an opening on one end for inserting thesecond end 8 of the hollow tube 2 of the integrated fusion cage andgraft delivery device. As opposed to prior art integrated fusion cageand graft delivery devices which have an opening at a second end that isopen to the longitudinal axis of the delivery device, the presentinvention comprises a lateral opening, which as shown in FIG. 5 allows asurgeon to eject bone mill into the lateral direction and thereby intothe opened areas of the disc space 40. A surgeon has the option torotate the direction of the opening in the second end 8 of the hollowtube 2 for ejecting additional bone graft to other open areas in thedisc space 40. Once the disc space 40 is substantially full of bonegraft, the surgeon may remove the hollow tube 2 without disturbing thedisc or anatomy of the patient. The surgeon may also accomplish thedelivery of bone graft without displacing any cage or other structuralimplantable device which may be present in or adjacent the disc space.One skilled in the art will appreciate that the hollow tube 2 furthercomprising a footing 11, and a second end opening for ejecting bonegraft in a generally lateral direction, may effect the delivery of bonegraft in a lateral direction simultaneous with delivery in alongitudinal direction.

Referring now to FIGS. 6-10, a preferred embodiment of the device isshown. In regard to FIG. 6, a integrated fusion cage and graft deliverydevice portion is shown, comprised of a hollow tubular member 2, whichhas a first proximate end 6 and a second distal end 8, with a generalhollow structure therebetween. The generally hollow tube 2 is shown withone of two lateral openings at the distal end 8 of the tubular member 2viewable (the other is viewable in FIG. 7). Also in FIG. 6, the plungermember 12 is shown. The manner of insertion of plunger member 12 intotubular member 2 is also provided. Thus, as shown in FIG. 6, the hollowtube 2 allows bone graft material to be inserted into the opening 4 atthe proximal end 6 of the hollow tube 2, and ultimately exited from thehollow tube 2 through the second distal end 8 from the lateral openingsat the distal end 8 of the hollow tubular member 2.

Furthermore regarding FIG. 6, a preferred embodiment of the distal end10 of the tubular member 2 and the distal end 20 of the plunger member12 is provided. The configuration provided, a wedge-shaped end 50 of thetubular member and a wedge-shaped end of the plunger 52, allowssubstantially all of the bone graft material to be removed and thusinserted into the surgical area when the plunger 2 is fully insertedinto the tubular member 2. The wedge-shaped feature 50 of the distal end10 of the tubular member 2 and the wedge-shaped end 52 of the distal end20 of the plunger member 12 is discussed in additional detail withrespect to FIGS. 8 and 9 below. The ability to remove substantially allof the bone graft material is an important feature of the inventionbecause bone graft material is traditionally expensive and may requiresurgery to obtain.

Referring now to FIG. 7, a perspective view of a preferred embodiment ofthe hollow tubular member 2 is provided. Consistent with FIG. 6, thegenerally hollow tube 2 is shown with one of two lateral openings at thedistal end 8 of the tubular member 2 viewable (the other is viewable inFIG. 6). Thus, in operation the hollow tube 2 allows bone graft materialto be inserted into the opening 4 at the proximal end 6 of the hollowtube 2, and ultimately exited from the hollow tube 2 through the seconddistal end 8 from the lateral openings at the distal end 8 of the hollowtubular member 2. In this configuration, bone graft material is ejectedinto the surgical area in two lateral directions. One skilled in the artwill appreciate that the openings at the distal end 8 of the hollowtubular member 2 need not be positioned exclusively on one or morelateral sides of the distal end 8 of the tubular member to allow bonegraft material to be provided to the surgical site in other than apurely axial or longitudinal direction. Further, one skilled in the artwill appreciate that the specific absolute and relative geometries andnumbers of lateral openings may vary, for example the distal end 8 ofthe tubular member 2 may have more than two openings that are ofdifferent shape (e.g. oval, rectangular).

Referring now to FIG. 8, an elevation view of the wedge-shaped distalend 50 of the tubular member 2 is provided. In this embodiment, theproximal end of the plunger would conform to the same shape, to allowclose fitting of the plunger and the hollow tubular member. Thiscontoured plunger, corresponding to the contoured tubular member, servesseveral purposes: First, it maintains the plunger in a desirablerotational position with respect to the hollow tube (i.e., prevent theplunger from inadvertently or intentionally being manipulated to rotateabout the longitudinal axis of the hollow tube); Second, it ensure thatwhen the plunger is fully inserted, the plunger removes substantiallyall of the bone graft material from the hollow tube. Also, the contouredplunger, corresponding to the contoured tubular member, allows immediateidentification of the orientation of the device, and more specificallythe direction of eject of the bone graft material into the surgicalarea. One skilled in the art will appreciate that the plunger need notterminate in a wedge-shape surface to effect the substantial removal ofall of the bone graft material placed into the hollow tube; morespecifically, any shape that allows conformance between the internalcontour of the distal end of the hollow tube and the distal end of theplunger will effect the substantial removal of the bone graft material.

Referring now to FIG. 9, an elevation view of the opening 4 of thedistal end 6 of the hollow tubular member 2 is provided. As shown inFIG. 9, the opening 4 at the proximal end 6 of the hollow tube 2 allowsdeposit of bone graft material. In this configuration, the cross-sectionof the opening 4 at the proximal end 6 of the hollow tube 2 is generallysquare. Although a generally square cross-section is depicted, thecross-section need not be limited to a generally square shape. Forexample, cross-sections of an oval shape or those with at least onedefined angle to include obtruse, acute, and right angles can provide ashape in some situations that is more congruent with the size or shapeof the annulotomy of a particular disc space.

Referring to FIGS. 10A-D, sequential elevation views of thesquare-shaped embodiment of the integrated fusion cage and graftdelivery device 1 are provided, depicting the complete insertion of theplunger 12 into the hollow tubular member 2. In each of FIGS. 10A-D, thewedge-shaped distal end 50 of the tubular member 2 is depicted. Also,each of FIGS. 10A-D depict the additional length of the plunger element12 when inserted into the tubular member 2. FIG. 10A shows one of twolateral openings at the distal end 8 of the hollow tubular member 2.FIG. 10C shows another of the two lateral openings at the distal end 8of the hollow tubular member 2. One skilled in the art will appreciatethat the openings at the distal end 8 of the hollow tubular member 2need not be positioned exclusively on one or more lateral sides of thedistal end 8 of the tubular member to allow bone graft material to beprovided to the surgical site in other than a purely axial orlongitudinal direction. Further, one skilled in the art will appreciatethat the specific absolute and relative geometries and numbers oflateral openings may vary, for example the distal end 8 of the tubularmember 2 may have more than two openings that are of different shape(e.g. oval, rectangular).

Referring to FIGS. 11A-D, a fusion cage 60 of an integrated fusion cageand graft delivery device 1 portion is shown, which is comprised of aintegrated fusion cage 60 that comprises a first proximal end 62 and asecond distal end 64 wherein the first proximal end contains an opening66 adapted to allow fitting and/or engagement to the distal end 8 of thehollow tube 2. This fitting and/or engagement may be over the externalsurface of the hollow tube 2 or inside the interior of the hollow tube2. Further, the integrated fusion cage 60 may comprise one or moremedial openings 68 that align with one or more openings at the distalend 8 of the hollow tube 2. Further, the integrated fusion cage 60 maycontain non-smooth surfaces, such as belts or striations, along one ormore medial surfaces 70 of the integrated fusion cage 60. The integratedfusion cage 60 is configured such that when a plunger 12, once fullyinserted in to the hollow tube 2, is substantially congruent with thehollow interior portion of the hollow tube 2, e.g. both the plunger 12and the hollow tube 2 are substantially the same shape and/or class andbone graft material is delivered through the integrated fusion cage 60into the surgical area.

In a preferred embodiment, the fusion cage 60 has a tapered tip, andseveral open channels along the medial and lateral surfaces. In apreferred embodiment, the fusion cage 60 and/or the bone graft deliveryportion of the integrated fusion cage and graft delivery device is ofoblong or rectangular or square shape. The integrated fusion cage andgraft delivery device 1 is designed to avoid blocking or impacting bonegraft material into a surgical disc space, thereby limiting the bonegraft material that may be delivered, and not allowing available fusionspace to be fully exploited for fusion.

In a preferred embodiment, the fusion cage 60 has a keel-shaped tip toseparate disk and prevent annular penetration. Also, the fusion cage 60may have dual portals for bone graft discharge, with the medial openings68 larger than the lateral openings 69. Further, the fusion cage may bedesigned in variable heights and lengths so that it fits snugly into theprepared disk space.

Referring now to FIGS. 12A-C, two alternate embodiments of the fusioncage 60 are provided. FIG. 12A shows an embodiment of the integratedfusion cage 60 with a second distal end 64 tapered to a flat rectangularshape end. FIG. 12B shows an embodiment of the integrated fusion cage 60with a second distal end 64 tapered to a wedged-shaped end. Such aconfiguration would be, for example, would be conformal with thewedge-shaped second end 50 of the hollow tube 2, as shown in FIGS. 6-8.FIG. 12C shows an embodiment of the integrated fusion cage 60 with beltsof striations imparted to the upper medial surface 70 of the fusion cage60.

In regard to FIG. 13, an integrated fusion cage and graft deliverydevice 1 is shown, comprised of a hollow tubular member 2, which has afirst proximate end 6 and a second distal end 8, with a general hollowstructure therebetween. The generally hollow tube 2 is shown with one oftwo lateral openings at the distal end 8 of the tubular member 2viewable. Also in FIG. 13, the plunger member 12 is shown and the fusioncage 60. The manner of insertion of plunger member 12 into tubularmember 2 is also provided, as is the manner of insertion of fusion cage60 over tubular member 2 and into the fusion cage first end opening 66.Thus, as shown in FIG. 13, the hollow tube 2 allows bone graft materialto be inserted into the opening 4 at the proximal end 6 of the hollowtube 2, and ultimately exited from the hollow tube 2 through the seconddistal end 8 from the lateral openings at the distal end 8 of the hollowtubular member 2 and through the medial openings 68 and/or the lateralopenings 69 of the fusion cage 60. In one embodiment as shown in FIG.13, the lateral openings at the distal end 8 of the hollow tubularmember 2 are preferably disposed within a distance from the distal end 8not exceeding 25% of the total distance (or length) of the hollow tubemember 2, more preferably not exceeding 15% of this identified distance,and most preferably not exceeding 10% of this identified distance. Inone embodiment as shown in FIG. 13, the lateral openings at the distalend 8 of the hollow tubular member 2 are preferably disposed within adistance from the distal end 8 not exceeding 10 cm of the total distance(or length) of the hollow tube member 2, more preferably not exceeding 8cm of this identified distance, and most preferably not exceeding 5 cmof this identified distance.

Referring to FIGS. 14A-D, sequential elevation views of thesquare-shaped embodiment of the integrated fusion cage and graftdelivery device 1 are provided, depicting sequential elevation views ofthe integrated fusion cage and graft delivery device 1 with the plungerportion 12 fully inserted into the tubular portion 2 and the fusion cage60 fully inserted over the tubular portion 2. One skilled in the artwill appreciate that the openings at the distal end 8 of the hollowtubular member 2 need not be positioned exclusively on one or morelateral sides of the distal end 8 of the tubular member to allow bonegraft material to be provided to the surgical site in other than apurely axial or longitudinal direction. Further, one skilled in the artwill appreciate that the specific absolute and relative geometries andnumbers of lateral and medial openings may vary, for example the distalend 8 of the tubular member 2 may have more than two openings that areof different shape (e.g. oval, rectangular).

Referring to FIGS. 15A-D, a fusion cage 60 of an integrated fusion cageand graft delivery device portion is shown, which is comprised of aintegrated fusion cage 60 that comprises a first proximal end 62 and asecond distal end 64 wherein the first proximal end contains an opening66 adapted to allow fitting and/or engagement to the distal end 8 of thehollow tube 2. This fitting and/or engagement may be over the externalsurface of the hollow tube 2 or inside the interior of the hollow tube2. Further, the integrated fusion cage 60 may contain non-smoothsurfaces, such as belts or striations, along one or more medial surfaces70 of the integrated fusion cage 60. The integrated fusion cage 60 isconfigured such that when a plunger 12, once fully inserted in to thehollow tube 2, is substantially congruent with the hollow interiorportion of the hollow tube 2, e.g. both the plunger 12 and the hollowtube 2 are substantially the same shape and/or class and bone graftmaterial is delivered through the integrated fusion cage 60 into thesurgical area.

In a preferred embodiment, the fusion cage 60 has a tapered tip, andseveral open channels along the medial and lateral surfaces. In apreferred embodiment, the fusion cage 60 is of a square shape and thebone graft delivery portion of the integrated fusion cage and graftdelivery device is of a cylindrical shape. The integrated fusion cageand graft delivery device 1 is designed to avoid blocking or impactingbone graft material into a surgical disc space, thereby limiting thebone graft material that may be delivered, and not allowing availablefusion space to be fully exploited for fusion.

In a preferred embodiment, the fusion cage 60 has a keel-shaped tip toseparate disk and prevent annular penetration and has internal ramps 72which assist in directing the bone graft material to one or more lateralopenings 69. As the plunger 12 is inserted into the hollow tube 2, bonegraft material is directed by the fusion cage internal ramps 72 out thelateral openings 69, and bone additionally bone graft material may flowout the one or more medial openings 68. The plunger end 18 may beconfigured to be conformal with the internal ramps 72 of the fusion cage60, as depicted in FIG. 15B. Also, the fusion cage 60 may have dualportals for bone graft discharge, with the medial openings 68 largerthan the lateral openings 69. Further, the fusion cage may be designedin variable heights and lengths so that it fits snugly into the prepareddisk space.

In a preferred embodiment as shown in FIGS. 15B-D, the hollow tube 2 isof cylindrical shape and includes one or more locking tabs 80 configuredto engage one or more locking slots 82 of the fusion cage 60. Thelocking tabs 80 may permanently or not permanently engage the lockingslots 82, and may be of shape to include rectangular, circular andoblong. The instruments used with the integrated fusion cage and graftdelivery device described above in its varying embodiments may includeone or more tamps, preferably having a configuration which at least inpart corresponds in shape and contour of the hollow tube portion of thedelivery device. The one or more tamps may be adapted to correspondfurther to the shape and contour of the graspable end of the plunger,for use in driving the plunger through the hollow tube portion of thedelivery device to ensure any remaining bone graft located in the hollowtube is delivered to the graft receiving area.

In the embodiment of the device of FIG. 16, the hollow tube 2 engageswith the fusion cage 60 via a break-off collar 90 and the plunger 12inserts into the interior of the hollow tube 2. The plunger 12 isdepicted partially inserted into the hollow tube 2. The break-off collar90 may be severed by any of several means, to include application oftorsion and/or rotational force and/or lateral force to break-off collar90, for example by twisting on the hollow tube 2 and/or the plunger 12.

In the embodiment of the device of FIG. 17A-B, the hollow tube 2 engageswith a connector conduit 100 which in turn connects with the fusion cage60 via a break-off collar 90. One or more connectors 102 connect thehollow tube 2 with the connector conduit 100. The hollow tube 2 fitsover the connector conduit 100. The one or more connectors 102 fitthrough the hollow tube 2 and the connector conduit 100. The break-offcollar 90 may be severed by any of several means, to include applicationof torsion and/or rotational force and/or lateral force to break-offcollar 90, for example by twisting on the hollow tube 2 and/or theplunger 12. In one embodiment of the connector conduit 100, as shown inFIG. 17B, the connector conduit 100 is of circular cross-section.

Referring to FIGS. 18A-D, sequential elevation views of thesquare-shaped embodiment of the integrated fusion cage and graftdelivery device 1 are provided, depicting sequential elevation views ofthe integrated fusion cage and graft delivery device 1 with telescopingtubular portion 2 and the fusion cage 60 fully inserted over the tubularportion 2. One skilled in the art will appreciate that the openings atthe distal end 8 of the hollow tubular member 2 need not be positionedexclusively on one or more lateral sides of the distal end of thetubular member to allow bone graft material to be provided to thesurgical site in other than a purely axial or longitudinal direction.

In an embodiment of the invention particularly suited for ALIFprocedures, a fusion cage 110 as shown in FIGS. 19A-D comprises a hollowinternal chamber 114 in fluid communication with bone graft dischargeportals 112 and a charging portal 116, which comprises a break-offcollar in some embodiments such as those depicted in FIGS. 17A-D. Thefusion cage 110 has a substantially cylindrical shape, with thedischarge portals 112 located opposite each other on the curved lateralportion of the fusion cage 110 and the charging portal 116 locatedsubstantially in between the discharge portals 112 on the curvedanterior portion of the fusion cage 110. The curved posterior portion ofthe fusion cage 110 is substantially devoid of portals from the internalchamber 114 to the exterior of the fusion cage 110. The charging portal116 is adapted to receive a hollow tube such as the hollow tube 2 shownin other embodiments described herein. Bone graft material enters theinternal chamber 114 through a hollow tube connected to the chargingportal 116, and exits the internal chamber 114 through the dischargeportals 112. The discharge portals 112 are positioned so that when thefusion cage 110 is properly positioned in between two vertebrae, bonegraft material discharged therethrough fills the space in between thevertebrae on the lateral sides of the spine, but does not discharge intoor fill the anterior or posterior space in between the vertebrae. Inembodiments of fusion cage 110 comprising a break-off collar, once thefusion cage 110 is properly positioned and the desired amount of bonegraft material has been inserted into the chamber 114 and dischargedthrough the discharge portals 112, the break-off collar is severed fromthe fusion cage 110 (as described with respect to other embodimentsherein) and removed from the patient's body.

In embodiments that do not comprise a break-off collar, the chargingportal 116 of fusion cage 110 is adapted to removably receive a hollowtube (such as the hollow tube 2 shown in other embodiments describedherein). For example, the walls of the charging portal 116 may bethreaded so that the hollow tube can be screwed into the charging portal116.

The fusion cage 110 preferably has a height of from about 8 millimetersto about 14 millimeters, and a diameter of less than about 36millimeters. The fusion cage 110 is made from polyether ether ketone(PEEK), titanium, a composite material, or any other material suitablefor implantation in a human body. The fusion cage 110 comprises, in someembodiments, ramps within internal chamber 114 to guide bone graftmaterial to discharge portals 112.

In an embodiment of the invention particularly suited for D-LIFprocedures, a fusion cage 120 as shown in FIGS. 20A-D comprises a hollowinternal chamber 124 in fluid communication with bone graft dischargeportals 122 and a charging portal 126, which in someembodiments—including the embodiment shown in FIGS. 20A-D—comprises abreak-off collar. The fusion cage 120 is substantially shaped as arectangular prism, with the discharge portals 122 located on oppositesides of the fusion cage 120 and the charging portal 126 located on alateral face of the fusion cage 120. The opposite lateral face of thefusion cage 120 is devoid of portals from the internal chamber 124 tothe exterior of the fusion cage 120. The charging portal 126 is adaptedto receive a hollow tube such as the hollow tube 2 shown in otherembodiments described herein. Bone graft material enters the chamber 124through a hollow tube connected to the charging portal 126, and exitsthe internal chamber 124 through the discharge portals 122. Thedischarge portals 122 are positioned so that when the fusion cage 120 isproperly positioned in between two vertebrae, bone graft materialdischarged therethrough fills the space in between the vertebrae towardsthe anterior and posterior of the spine, but does not discharge into orfill the lateral space in between the vertebrae. As with otherembodiments described herein, in embodiments that comprise a break-offcollar, once the fusion cage 120 is properly positioned and the desiredamount of bone graft material has been inserted into the chamber 124through charging portal 126 and discharged through the discharge portals122, the break-off collar is severed from the fusion cage 120 (asdescribed with respect to other embodiments herein) and removed from thepatient's body.

In embodiments that do not comprise a break-off collar, the chargingportal 126 is adapted to removably receive a hollow tube (such as thehollow tube 2 shown in other embodiments described herein). For example,the internal walls of charging portal 126 may be threaded so that thehollow tube can be screwed into the charging portal 126.

The fusion cage 120 preferably has a height of from about 8 millimetersto about 14 millimeters, and a length of from about 22 millimeters toabout 36 millimeters. The fusion cage 120 is made from polyether etherketone (PEEK), titanium, a composite material, or any other materialsuitable for implantation in a human body. The fusion cage 120comprises, in some embodiments, ramps within internal chamber 124 toguide bone graft material to discharge portals 122.

Referring now to FIGS. 21A-D, in embodiments of the inventionparticularly suited for use in connection with a vertebrectomy, a fusioncage 130 comprises a substantially cylindrical wall surrounding aninternal chamber 134. Thus, the fusion cage 130 has a substantiallycylindrical shape. Internal chamber 134 is open at the top and thebottom of fusion cage 130, and lateral portions 132 of the cylindricalwall of the fusion cage 130 are porous to bone graft material (i.e. bonegraft slurry). Anterior and posterior portions 138 of the cylindricalwall of fusion cage 130 in between porous portions 132 are impervious tobone graft material. A charging portal 136—which in some embodiments,including the embodiment shown in FIGS. 21A-D, comprises a break-offcollar—is positioned on an impervious portion 138 of fusion cage 130.The charging portal 136 is adapted to receive a hollow tube such as thehollow tube 2 shown in other embodiments described herein. Bone graftmaterial enters the chamber 134 through a hollow tube connected to thecharging portal 136, and exits the chamber 134 through porous wallportions 132. The porous wall portions 132 are positioned so that whenthe fusion cage 130 is properly positioned in between two vertebrae,bone graft material discharged therethrough fills the space in betweenthe vertebrae on either side of the spine, but the impervious wallportions 138 prevent bone graft material from discharging into theanterior or posterior space in between the vertebrae, thus preventingbone graft material from pushing against the spinal cord. In embodimentsof fusion cage 130 comprising a break-off collar, once the fusion cage130 is properly positioned and the desired amount of bone graft materialhas been inserted into the chamber 134 through charging portal 136 anddischarged through the porous wall portions 132, the break-off collar136 is severed from the fusion cage 130 (as described with respect toother embodiments herein) and removed from the patient's body.

In embodiments that do not comprise a break-off collar, the chargingportal 136 is adapted to removably receive a hollow tube (such as thehollow tube 2 shown in other embodiments described herein). For example,the internal walls of the charging portal 136 may be threaded so thatthe hollow tube can be screwed into the charging portal 136.

The fusion cage 130 preferably has a height equal to or greater than thevertebra or vertebrae it is intended to replace, and a diameter of lessthan about 36 millimeters. The fusion cage 130 is made of polyetherether ketone, titanium, a composite material, or any other materialsuitable for implantation in a human body. In some embodiments, ramps inthe internal chamber 134 guide the bone graft material to the porouslateral faces 132.

Referring now to FIGS. 22-33, another embodiment of the device fordelivering bone graft is provided. In regard to FIGS. 22-28, integratedfusion cage and graft delivery device 1 is shown. FIG. 22 is aperspective view of the device 1, FIG. 23 a perspective exploded view,FIG. 24 a top plan view, FIG. 25 a front elevation view, FIG. 26 a rightelevation view, FIG. 27 is a bottom plan view, and FIG. 28 is across-sectional view of section A-A of FIG. 25.

Device 1 is comprised of a hollow tubular member or hollow tube 2, aplunger 12 which fits within the hollow tube 2, and a funnel 30. Thefunnel 30 engages the upper or distal or first end 6 of the hollow tube,and comprises a sleeve 32 and opening 34. Medical material, such as bonegraft material, is inserted into opening 34 of funnel 30, which in turnenters hollow tube 2. Hollow tube 2 comprises hollow tube first exteriorsurface 3, hollow tube second exterior surface 5, first end 6, secondend 8, and hollow tube first distal opening 7. Hollow tube 2 isgenerally of symmetrical shape such that first exterior surface 3comprises two such surfaces opposite or at 180 degrees from one another,and second exterior surface 5 comprises two such surfaces opposite or at180 degrees from one another. Also, hollow tube first distal opening 7is positioned on each of two opposite sides of hollow tube 2 at secondend 8, each opening from hollow tube first exterior surface 3.

Funnel 30 is configured with sleeve 32 such that funnel 30 may bepositioned at second end 8 of hollow tube 2 such that hollow tube mayfit through funnel 30, enabling funnel 30 to move along hollow tube 2from second end 8 of hollow tube 2 to first end 6 of hollow tube 2 untilfunnel 30 engages first end 6 of hollow tube, such as at protrusion orshelf depicted in FIG. 23.

Plunger 12 comprises handle 16 at upper or proximal end of plunger 12,plunger distal or second end 18. Plunger second end 18 comprises distalfirst surface 13, distal second surface 14 and distal third (or bottom)surface 15. Plunger second end 18 is generally of symmetrical shape suchthat distal first surface 13 comprises two such surfaces opposite or at180 degrees from one another, and distal third surface 15 comprises twosuch surfaces opposite or at 180 degrees from one another. Plunger 12 isconfigured such that second end 18 forms a congruent or conformalengagement with the interior of the hollow tube 2. Stated another way,the plunger second end 18 fits within the hollow tube 2 so as to slidewithin the hollow tube with minimal to no effective spacing between theexterior surface of the plunger second end 18 and the interior of thehollow tube 2, thereby forcing through bone graft material positioned inthe hollow tube 2 through the hollow tube when the plunger 12 (and thusits second end 18) is axially moved from hollow tube first end 6 tohollow tube second end 8.

In regard to FIGS. 29-31, further features of the plunger 12 aredescribed. FIG. 29 is a front elevation view of the plunger element ofthe device shown in FIG. 22, FIG. 30 is a cross-sectional view ofsection B-B of FIG. 29, and FIG. 31 is a cross-sectional of section C-Cof FIG. 29. Plunger 12 comprises handle 16 at upper or proximal end ofplunger 12, plunger distal or second end 18. Plunger second end 18comprises distal first surface 13, distal second surface 14 and distalthird (or bottom) surface 15. Plunger medial portion 17 forms a crossconfiguration, as depicted in FIG. 30, such that distal first surfaces13 are of reduced width relative to width at second end 18. Similarly,plunger distal second surfaces 14, at plunger medial portion 17, are ofreduced width relative to width at second end 18. At distal end 18 ofplunger 12, plunger cross-section is a rectangle, as depicted in FIG.31.

In regard to FIGS. 32 and 33, additional detail of the distal portion ofdevice 1 are provided. FIG. 32 is a detailed view of a portion of thedevice 1 shown in FIG. 22 and FIG. 33 is a cross-sectional view ofsection D-D of FIG. 32. Each of FIGS. 32 and 33 depict the device 1 whenthe plunger 12 is fully inserted into the hollow tube 2, and the plungerdistal third surface 15 has engaged and is in contact with the hollowtube distal interior ramp 9. Hollow tube distal interior ramp 9comprises hollow tube distal interior ramp surfaces 9A, symmetricallypositioned about the middle of the hollow tube second end 8. Hollow tubedistal interior ramp surfaces 9A are of curvilinear shape forming aterminus, and urge bone graft material, when disposed within the hollowtube 2, to substantially exit the pair of first distal openings 7 of thedevice 1.

In one embodiment of the device, the width of the hollow tube secondexterior surface 5 is between 10 and 14 mm. In a preferred embodiment,the width of the hollow tube second exterior surface 5 is between 11 and13 mm. In a most preferred embodiment, the width of the hollow tubesecond exterior surface 5 is between 11.5 mm and 12.5 mm. In a preferredembodiment, the width of the hollow tube second exterior surface 5 is 12mm.

In one embodiment of the device, the width of the hollow tube firstexterior surface 3 is between 6 and 10 mm. In a preferred embodiment,the width of the hollow tube first exterior surface 3 is between 7 and 9mm. In a most preferred embodiment, the width of the hollow tube firstexterior surface 3 is between 7.5 mm and 8.5 mm. In a preferredembodiment, the width of the hollow tube first exterior surface 3 is 8mm.

In one embodiment of the device, the ratio of the width of the hollowtube second exterior surface 5 and the width of the hollow tube firstexterior surface 3 is between 1.7 and 1.3. In a preferred embodiment,the ratio of the width of the hollow tube second exterior surface 5 andthe width of the hollow tube first exterior surface 3 is between 1.6 and1.4. In a most preferred embodiment, the ratio of the width of thehollow tube second exterior surface 5 and the width of the hollow tubefirst exterior surface 3 is between 1.55 and 1.45. In one embodiment,the ratio of the width of the hollow tube second exterior surface 5 andthe width of the hollow tube first exterior surface 3 is 1.5.

In one embodiment of the device, the width of the interior of the hollowtube major axis (located adjacent the second exterior surface 5) isbetween 9 and 13 mm. In a preferred embodiment, the width of theinterior of the hollow tube major axis is between 10 and 12 mm. In amost preferred embodiment, the width of the interior of the hollow tubemajor axis is between 10.5 mm and 11.5 mm. In a preferred embodiment,the width of the interior of the hollow tube major axis is 11 mm.

In one embodiment of the device, the width of the interior of the hollowtube minor axis (located adjacent the first exterior surface 3) isbetween 5 and 9 mm. In a preferred embodiment, the width of the interiorof the hollow tube minor axis is between 6 and 8 mm. In a most preferredembodiment, the width of the interior of the hollow tube minor axis isbetween 6.5 mm and 7.5 mm. In a preferred embodiment, the width of theinterior of the hollow tube minor axis is 7 mm.

In one embodiment of the device, the ratio of the width of the interiorof the hollow tube major axis and the width of the interior of thehollow tube minor axis is between 1.7 and 1.3. In a preferredembodiment, the ratio of the width of the interior of the hollow tubemajor axis and the width of the interior of the hollow tube minor axisis between 1.6 and 1.4. In a most preferred embodiment, the ratio of thewidth of the interior of the hollow tube major axis and the width of theinterior of the hollow tube minor axis is between 1.55 and 1.45. In oneembodiment, the ratio of the width of the interior of the hollow tubemajor axis and the width of the interior of the hollow tube minor axisis 1.5.

It should be noted that the rectangular configuration of the hollow tubeaffords several advantages over conventional circular configuration. Forexample, for a surgical area with smallest dimension set at a width of 8mm with thickness dimension 0.5 mm, a conventional circular device (withresulting interior diameter of 7 mm or a radius of 3.5 mm) would realizea surface area of 38.48 mm². Applicants' device would carry interiordimension of 7 mm by 11 mm for a surface area of 77 mm, an increasedsurface area factor of 2.0, thereby resulting in more bone graftmaterial delivery, because, among other things, a given volume of bonegraft encounters less surface area of the interior of a particulardevice which results in, among other things, reduced chance of jammingof bone graft material within the device.

In one embodiment, a one or more edges of the device are rounded. Forexample, the exterior edges of the hollow tube are rounded, and/or theinterior edges of the hollow tube are rounded (in which case the edgesof the plunger, at least at the plunger distal end, are identicallyrounded to ensure a congruous or conformal fit between the edges of theplunger and the interior of the hollow tube so as to, among otherthings, urge the majority of bone graft material to move through thehollow tube).

In one embodiment, the handle 16 of plunger is a planar disk shape, asdepicted in FIG. 23. In another embodiment, handle 16 is not planar. Forexample, handle 16 is angled so as to conform to interior of funnel 30when the plunger 12 is fully inserted into hollow tube 2.

In one embodiment, the hollow tube distal interior ramp surfaces 9A arelinear shape, that is, forming a triangle in cross-section. In anotherconfiguration, the hollow tube distal interior ramp surfaces 9A are ofany shape that urges egress of bone graft material contained in thehollow tube to exit the interior of the hollow tube through the pair offirst distal openings 7 of the device 1.

A bone graft tamping device may also be provided, which is adapted to betelescopically inserted into the hollow tube after the plunger isremoved from the hollow tube. The bone graft tamping device, accordingto this embodiment, may include one or more longitudinal channels alongthe outer circumference of the bone graft packer for permitting anytrapped air to flow from the bone graft receiving area to the graspableend of the hollow tube during packing of bone graft. The bone graftpacker may further include a handle at one end designed ergonomicallyfor improving ease of use. The bone graft packer in this embodimentthereby facilitates packing of bone graft within the hollow tube.

The hollow tube may also be fitted with a passageway wherein a surgicaltube or other device may be inserted, such as to deliver a liquid to thesurgical area or to extract liquid from the surgical area. In such anembodiment, the plunger is adapted in cross-section to conform to thehollow tube's cross-section.

In another embodiment of the present invention, a kit of surgicalinstruments comprises a plurality of differently sized and/or shapedhollow tubes and a plurality of differently sized and/or shapedplungers. Each of the plungers correspond to at least one of the hollowtubes, whereby a surgeon may select a hollow tube and a plunger whichcorrespond with one another depending upon the size and shape of thegraft receiving area and the amount or type of bone graft to beimplanted at such area. The corresponding hollow tubes and plungers areconstructed and arranged such that bone graft can be placed within thehollow tubes with the plungers, and inserted nearly completely into thehollow tubes for removing substantially all of the bone graft materialfrom the hollow tubes, such as in the preferred embodiments for theplunger described above. The use of more than one hollow tube/plungercombination permits at least two different columns of material to beselectably delivered to the targeted site, e.g. one of bone graftmaterial from the patient and another of Bone Morphogenetic Protein(BMP), or e.g. two different types of bone graft material or onedelivering sealant or liquid. Also, one or both hollow tubes could bepreloaded with bone graft material.

The kit of surgical instruments may comprise a plurality of differentlysized and/or shaped graft retaining structures, each corresponding to atleast one hollow tube and at least one plunger.

The bone graft receiving area can be any area of a patient that requiresdelivery of bone graft. In the preferred embodiment, the bone graft isdelivered in a partially formed manner, and in accordance with anotheraspect of the present invention, requires further formation afterinitial delivery of the bone graft.

Another embodiment of the present invention provides a method by which ahollow tube and a plunger associated with the hollow tube are providedto facilitate delivery of the bone graft to a bone graft receiving area.

According to one embodiment, the present invention provides a bone graftdelivery system, by which a hollow tube and/or plunger assembly may beprepared prior to opening a patient, thus minimizing the overall impactof the grafting aspect of a surgical implantation or other procedure.Moreover, the hollow tube may be made to be stored with bone graft in itfor a period of time, whether the tube is made of plastic, metal or anyother material. Depending upon the surgical application, it may bedesirable to only partially fill the tube for storage, so that a plungercan be at least partially inserted at the time of a surgery.

Thus, the integrated fusion cage and graft delivery device may eithercome with a pre-filled hollow tube, or a non-filled hollow tube, inwhich the surgeon will insert bone graft received from the patient(autograft), or from another source (allograft). In either case, thesurgeon may first remove any wrapping or seals about the hollow tube,and/or the pre-filled bone graft, and insert the hollow tube into thepatient such that the second end of the hollow tube is adjacent the bonegraft receiving area. Once the hollow tube is in place, and the openingat the second end of the hollow tube is oriented in the direction of thedesired placement of bone graft, the surgeon may then insert the secondend of the plunger into the opening at the first end of the hollow tube,and begin pressing the second end of the plunger against the bone graftmaterial in the hollow tube. In this fashion, the plunger and hollowtube cooperate similar to that of a syringe, allowing the surgeon tosteadily and controllably release or eject bone graft from the secondend of the hollow tube as the plunger is placed farther and farther intothe opening in the hollow tube. Once the desired amount of bone grafthas been ejected from the hollow tube (for in some instances all of thebone graft has been ejected from the hollow tube) the surgeon may removethe plunger from the hollow tube, and complete the surgery. In certainoperations, the surgeon may elect to place additional bone graft intothe hollow tube, and repeat the steps described above. Furthermore, thepre-filled bone graft elements may be color-coded to readily identifythe type of bone graft material contained therein.

According to the embodiment described in the preceding paragraph, thepresent invention may be carried out by a method in which access isprovided to a graft receiving area in a body, bone graft is placed intoa hollow tube having a first end and a second end, the hollow tube,together with the bone graft, is arranged so that the first end of thehollow tube is at least adjacent to the graft receiving area and permitslateral or nearly lateral (n relation to the longitudinal axis of thehollow tube and plunger assembly) introduction of bone graft to thegraft receiving area. This method prevents loss of bone graft due toimproper or limited orientation of the integrated fusion cage and graftdelivery device, and further allows a user to achieve insertion of adesired quantity of bone graft by way of the contoured plunger andhollow tube configuration described according to preferred embodimentsherein.

The method of the present invention may also be carried out by providinga hollow tube having a first end and a second end, constructed so thatit may receive a measurable quantity of bone graft, and so that thefirst end may be arranged at least adjacent to a bone graft receivingarea, and so that bone graft can be delivered from the first end of thehollow tube through the second end of the hollow tube and eventually tothe bone graft receiving area upon movement of the plunger in agenerally downward direction through the hollow tube (i.e., in adirection from the first end to the second end). According to thisembodiment, a graft retaining structure may also be provided for use inconnection with the contoured edge of the plunger, such that the graftretaining structure is positioned between the contoured edge of theplunger and the bone graft, but which is adhered to the bone graft andremains at the graft receiving area following removal from the hollowtube. Furthermore, this graft retaining structure may also be employedwith another tool, such as a graft packer, which is employed eitherbefore or after the hollow tube is removed from the graft receivingarea.

In another embodiment, the one or more plungers corresponding to the oneor more hollow tubes are positioned with distal ends near the proximateend of the horizontal tube before use, said plungers having a detent toretain plunger in ready position without undesired movement beforesurgeon chooses which one or more plungers to extend through hollowhorizontal tube and deliver bone graft material and/or desired materialto the surgical area.

According to another embodiment of the present invention, a hollow tubeand plunger assembly is provided in which the hollow tube and/or theplunger assembly is disposable. Alternatively, the tube may be made of abiocompatible material which remains at least partially in the patientwithout impairing the final implantation. Thus, the hollow tube may beformed from a material that is resorbable, such as a resorbable polymer,and remain in the patient after implantation, so as not to interferewith the growth of the bone or stability of any bone graft or implant.

The current design preferably comprises a hollow tubular membercomprising a rounded edge rectangular shaft, which may be filled or ispre-filled with grafting material. The loading is carried out by theplunger. The rectangular design is preferable as it allows the largestsurface area device to be placed into the annulotomy site of a disk, butin other embodiments may be formed similar to conventional round shafts.The other preferred feature includes a laterally-mounted exit site forthe graft material. The combination of this design feature allowsdirection-oriented dispersion of the graft material. This allowsejection of the graft material into an empty disk space as opposed tobelow the hollow tube, which would tend to impact the material and notallow its spread through a disk space.

Another feature of this design is that a rectangular design allows theuser to readily determine the orientation of the device and thereby thedirection of entry of the bone graft material into the surgical area.However, such a feature may be obtained alternatively through exteriormarkings or grooves on the exterior on the hollow tube. Such exteriorgrooves or markings would allow use of a range of cross-sections for thedevice, to include a square, circle, or oval while allowing the user toreadily determine the orientation of the device relative to thedirection of entry of the bone graft material into the surgical area.

A further feature of this design is that an anti-perforation footing orshelf is paced on the bottom of the hollow tube to prevent annularpenetration and/or injury to the patient's abdomen or other anatomyadjacent the bone graft receiving area.

Another alternative embodiment to the design described herein includes aremovable funnel attachment. This allows easy loading of the cannulawith the funnel and with its removal easy visualization of the operatingsite without visual blockage through the microscope.

In another embodiment of the invention, all or some of the elements ofthe device or sections of all or some of the device may be disposable.Disposable medical devices are advantageous as they typically havereduced recurring and initial costs of manufacture.

In another embodiment of the device, the distal tip or end of theplunger device is composed of a different material to the rest of theplunger, so as the material at the distal end of the plunger issponge-like or softer-than or more malleable than the rest of theplunger so as upon engagement with the interior distal end of the hollowtube, the distal end of the plunger substantially conforms to theinterior configuration of the hollow tube. Similarly, the plunger distalend may be made of a material that is adaptable to substantially conformto the interior shape of the distal end of the hollow tube. Suchconfigurations enable substantially all of the material contained withinthe plunger to be delivered to the targeted site.

Another alternative embodiment to the design described herein includes anavigation aid on one or more surfaces of the tubular body to permitsurgeon to know how far the device has been inserted or to ensure properalignment relative to a transverse bone graft delivery site (i.e. discspace). Such capability is particularly important when the patient orsurgical area is not positioned immediately below the surgeon, ormultiple procedures are being performed. A navigation aid allows moreimmediate and reliable locating of the surgical area for receiving ofbone graft material. In one embodiment, the hollow tube is scored ormarked or provides some affirmative indication, actively or passively,to the surgeon to indicate degree of delivery of the material, e.g. bonegraft material, to the delivery site, and/or position of the plungerelement. For example, the exterior of the hollow tube could becolor-coded and/or provided with bars. In another embodiment, a computerand/or electro-mechanical sensor or device is used to provide feedbackto the surgeon to indicate degree of delivery of the material, e.g.amount of cc's of bone graft material, to the delivery site, and/orposition of the plunger element.

In another alternative embodiment to the design described herein, theplunger could include an activation device, which is often in a liquidor semi-liquid state, and that may be injected once the semi-solidportion of the morphogenic protein has been displaced by the movement ofthe plunger through the tubular body. That is, the plunger pushes thedry material, and once completed has a bulb or other device on theusable end to insert the liquid portion of the activating agent throughthe inner lumen within the plunger to evacuate the liquid from theplunger and out an opening at the non-usable end of the plunger so as tocontact the dry material already inserted into the disc space).

In one embodiment of the device, all or portions of the device aremanufactured using 3-D printing techniques. In another embodiment, allor portions of the device are made by injection molding techniques.

In one embodiment, the ratio of the surface area of the bottom tip ofthe plunger is approximately half the surface area of the two lateralopenings at the distal portion of the hollow tube.

In one embodiment, the device includes a supplemental means of grippingthe device, such as a laterally extending cylindrically-shaped handlethat engages the hollow tube.

In one embodiment, the material inserted into the hollow tube is anon-Newtonian fluid. In one embodiment, the device is adapted to acceptand deliver compressible fluids. In another embodiment, the device isadapted to accept and deliver non-compressible fluids.

In one embodiment, the upper portion of plunger is fitted with one ormore protrusions, which extends from the surface of the plunger so as toengage the upper surface of the hollow tube, to prevent the plunger fromengaging the distal interior portion of the hollow tube. In oneembodiment, the upper portion of plunger is fitted with one or moreprotrusions to prevent the plunger from engaging the apex of the hollowtube distal interior ramp surface.

In one embodiment, the funnel attaches to the upper portion of thehollow tube by a bayonet connection. In one embodiment, the funnelattaches to the upper portion of the hollow tube by an interference fit.In one embodiment, the funnel attaches to the upper portion of thehollow tube by a threaded connection. In one embodiment, the funnelattaches to the upper portion of the hollow tube by a slot/grooveconnection.

In one embodiment, the second end of hollow tube has one hollow tubedistal opening. In one embodiment, the second end of hollow tube has twohollow tube distal openings located on opposite sides. In oneembodiment, the second end of hollow tube has no more than two openings,the openings located on opposite sides.

In one embodiment, after bone graft material is delivered to a surgicalsite, a cavity approximately defined by the volume engaged by the devicewhen inserted into the surgical site is left in the surgical site uponremoval of the device from the surgical site. In one embodiment, theaforementioned cavity is then used as the site for insertion of a fusioncage.

Surprisingly, while conventional practice assumed that the amount ofmaterial that would be required, let alone desired, to fill a prepareddisc space with bone paste (or BMP, etc.) would be roughly equivalent tothe amount of material removed from such space prior to inserting acage, a present inventor discovered that far more bone graft materialcan be—and should preferably be—inserted into such space to achievedesired fusion results. The reasons why this basic under appreciationfor the volume of bone graft necessary to achieve optimal fusion resultsvary, but the clinical evidence arrived at via practice of the presentinvention compellingly demonstrates that more than doubling of theamount of bone graft material (and in some cases increasing the amountby 200%, 300% or 400% or more) than traditionally thought necessary orsufficient, is extremely beneficial to achieving desired results fromfusion procedures.

The ramifications of this simple yet dramatic discovery (documented inpart below) is part of the overall inventive aspect of the presentinvention, as it has been—to date—simply missed entirely by thepracticing spine surgeons in the field. The prospect of reduced returnsurgeries, the reduction in costs, time, and physical suffering bypatients, as well as the volume of legal complaints against surgeons andhospitals due to failed fusion results, is believed to be significant,as the evidence provided via use of the present invention indicates avast reduction in the overall costs involved in both economic resources,as well as emotional capital, upon acceptance and wide-spread use of thepresent invention. Insurance costs should thus decrease as the presentinvention is adopted by the industry. While the costs of infusingincreased amount of bone graft materials into the space of a patient'sdisc may at first appear to increase the costs of an individualoperation, the benefits achieved thereby will be considerable, includingthe reduction of repeat surgeries to fix non-fused spines. Thus,regardless of the actual tools and devices employed to achieve the endresult of attaining up to 100% more bone graft material being utilizedin fusion operations, (as well as other surgeries where previouslyunder-appreciated bone graft material delivery volumes have occurred)one important aspect of the present invention is directed to theappreciation of a previously unrecognized problem and the solutionthereto, which forms part of the inventive aspects of the presentinvention described and claimed herein.

In one embodiment, at least twice the amount of disk material removedfrom a surgical site is replaced with bone graft material. In apreferred embodiment, at least three times the amount of disk materialremoved from a surgical site is replaced with bone graft material. In amost preferred embodiment, at least three and a half times the amount ofdisk material removed from a surgical site is replaced with bone graftmaterial.

Experimental Results

The following experimental results are with respect to an apparatus andmethod for near-simultaneous and integrated delivery of bone graftmaterial in a patient's spine. These results are sample results and arenot intended to limit the invention.

Materials and Methods

During the time period from July 2010 through December 2012, a set ofpatients undergoing minimally invasive (MIS) transverse lumbar interbodyfusion (T-LIF) at the L4-5 and/or L5-S1 levels were studied for diskmaterial removed and BG delivered at each disk space during the surgicalprocedure. The diagnosis was spondylosis or spondylolisthesis in allpatients. A total of 63 patients with an average age of 56 years werestudied. There were 29 male and 34 female patients. Ninety-one diskspaces were analyzed. A single surgeon with the same surgical teamperformed all surgeries. The operations were carried out through a 22 mmcannula with microscopic control. The midline structures and spinousprocess attachments were left undisturbed. The disk space was debridedexhaustively using non-motorized, hand tools to bleeding subchondralbone. The debrided disk material was measured in a volumetric syringe.Bone Graft (BG) material consisting of silicated tricalcium phosphategranules and hyaluronic acid powder were mixed in a 1:1 ratio and localbone graft and bone marrow aspirate concentrate were added together toform a slurry. The slurry was measured volumetrically. Disk spacemobilization and distraction was carried out with serial impaction ofdistractor tools until appropriate disk height was achieved. Distractionranged from 8 mm to 14 mm, with the 10 mm or 12 mm height being mostcommonly observed.

The BG delivery tool of this disclosure was used to apply the BG slurryto the disk space. The embodiment had a rectangular cross section withthe same footprint as a small fusion cage (8 mm×12 mm). The tapered tipwas placed into the debrided disk space under microscopic control toallow for direct visualization, followed by the application of a snap-onfunnel for loading the BG. The BG slurry was then placed in the funneland the slurry was pushed into the disk space with the plunger. Thebiportal design of the delivery tool directed the slurry into thelateral areas of the prepared disk space, leaving a natural void for thefusion cage once the tool was removed. Once the disk space was filledentirely, the site of insertion was inspected for any BG material, whichmight have escaped the confines of the disk space. This material wasexcluded in the final measurement to ensure an accurate calculation ofBG delivery. Removal of the delivery tool provided an unobscured pathfor the fusion cage to be applied.

A polyether ether ketone, hollow interbody fusion cage of theappropriate size was then placed into the disk space. A minimallyinvasive, bilateral pedicle screw/rod system was applied prior to woundclosure. Average blood loss for the procedures was 127 ml±75 ml.

A two-tailed student's t-test was used to determine if any significantdifference existed between the volumes of disk material removed at L4-5versus L5-S1. The null hypothesis was that no significant differenceexisted between samples. Significance was set at p<0.05. The two-tailedt test was also used to determine whether a significant differenceexisted between volumes of BG delivery and disk material removed. Theformula [(BG delivered+graft volume of the fusion cage)/disk materialremoved] was used to generate the ratio of BG delivery versus diskmaterial removed.

In order to compare the volume of disk material removed during a T-LIFprocedure with a complete, surgical diskectomy, the volume of diskmaterial removed during L5-S1 anterior lumbar diskectomy was measuredvolumetrically. The L5-S1 disk was harvested and measured for patientsundergoing either anterior fusion or total disk replacement. Thematerial removed consisted of anterior and posterior annulus as well ascomplete nuclectomy, and represented more tissue (in terms of theannuli) than would be typically removed in a T-LIF procedure. There were29 anterior L5-S1 diskectomy patients. The age range, genderdistribution and diagnosis were the same as the T-LIF patients.

All study patients were followed up with anterior/posterior radiographsand a physical examination at 4 weeks, 12 weeks, 26 weeks and 52 weekspost surgery.

A visual analog scale (VAS) for pain was obtained at each visit and anOswestry Disability Index (ODI) was completed preoperatively and at 26weeks postoperatively.

Results

There were 58 L4-5 disk spaces and 33 L5-S1 disk spaces evaluated. Theaverage volumes of disk material harvested from L4-5 and L5-S1 were 4.1ml±2.2 ml and 2.8 ml±1.9 ml, respectively. The p-value for the student'stwo-tailed t-test was equal to 0.01, revealing a significant differencein terms of disk material removed between L4-5 and L5-S1. The range ofvolume was less than 1 ml to 14.5 ml. The comparison between diskmaterial removed and BG material inserted at L4-5 or at L5-S1demonstrated a significant difference (p<<0.001).

BG volume applied to L4-5 was 9.8 ml±3.3 ml. At L5-S1 it was 8.6 ml±3.2ml. The p-value for the student's two-tailed t-test was equal to 0.07,trending to a significant difference in bone graft applied between L4-5and L5-S1. The combined average was 9.2 ml±3.0 ml. The volume of BGapplied ranged from 4.5 ml to 19 ml. The formula of [(BG delivered+graftvolume of the fusion cage)/disk material removed] generated a surprisingresult: The amount of disk material removed compared to the amount of BGplaced in the disk space was not a 1:1 ratio, as would have beenempirically expected. At L4-5 the ratio was 3.4±2.2 and at L5-S1 it was4.7±2.7, as shown in FIGS. 34A-B, respectively. This was statisticallysignificant with a p-value of 0.02. With respect to the entire study,the ratio of BG inserted relative to disk material removed revealed thaton average 3.7±2.3 times as much BG was inserted into the disk space asdisk material removed. This finding was even more dramatic withcollapsed disk spaces where 1 ml of disk material harvest led to anaverage of 6.6 ml±0.9 ml of BG delivery, as shown in FIGS. 35A-B. Thevolume of BG delivery was asymptotically related to the volume of diskmaterial removed with 12.3 ml of disk material being delivered to a diskwhere 8.0 ml of disk was removed, as shown in FIGS. 35A-B.

The average volume of disk material removed during a T-LIF diskectomy atL5-S1 was 3.2 ml and the average volume of disk material from theanterior L5-S1 diskectomy was 8.1 ml. Dividing the average T-LIF volumeby the average anterior diskectomy (including annuli) volume revealedthat on average 34% of the disk material was removed at the time ofT-LIF at the L5-S1 disk space.

Because of the tapered tip of the BG delivery tool, it was possible toenter the most collapsed disk space without endplate injury. Thedelivery device did not jam with the application of the BG slurry. Theremovable funnel allowed direct visualization of the tool under themicroscope without obscuring its tip during insertion. Because thedelivery device applied BG out of its side portals, it provided anatural void for fusion cage insertion, and no cage jamming resultedduring impaction. BG delivery using the described tool took a fractionof the time (less than 2 minutes) usually devoted to depositing BG tothe disk space. There were no complications associated with the use ofthe BG delivery tool.

The average preoperative ODI measured 29±9 and the postoperative valuewas 21±8. A significant difference was not detected with p=0.06. The VASsimilarly improved with pre-operative score measuring 7.5±1.5 andpostoperative score 4.0±2.5. The postoperative VAS was statisticallysignificant relative to the corresponding preoperative value withp<0.05. Pseudoarthrosis developed in 7 disks in 4 patients (7.6%). Thepatients with 2-level pseudoarthrosis had a diagnosis of hypothyroidism.This diagnosis was also present in one of the single levelpseudoarthosis patients. The remaining pseudoarthrosis patients did nothave discernable risk factors (diabetes, tobacco consumption orobesity).

Discussion

There is substantial variation in fusion rates after T-LIF surgery withpseudoarthrosis rates varying from 23.1% to 2.9%. The reasons for therange of successful arthrodesis vary from surgical technique, includingBG preparation and application, to the way in which a pseudoarthrosis isdiagnosed—direct surgical exploration or by radiographic means. Reasonwould dictate that the volume of BG delivered to a prepared disk spacewould contribute positively to successful arthrodesis with inadequategrafting leading to pseudoarthrosis. Using hand tools and the goal ofdisk space debridement, a conservative estimate of 34% of disk removalwas observed in this study at the L5-S1 level. This substantialdifference represents the different goals of the procedures and providesa baseline for general disk space debridement for T-LIF procedures.

The statistically significant difference between the amount of diskmaterial removed from L4-5 versus L5-S1 correlates with the commonlyobserved radiographic finding of disk height at L4-5 being greater thanthat of L5-S1. Likewise, BG delivery to L4-5 was greater relative to theL5-S1 disk space. Although direct volume of BG insertion was greater inL4-5 relative to L5-S1, the ratio (BG delivered/disk material removed)was higher at L5-S1 (4.7±2.7) than at L4-5 (3.4±2.2). This was astatistically significant difference (p<0.02) and corresponds with themore collapsed disk spaces demonstrating a higher percentage of BGdelivery (see FIGS. 34A-B).

On average, 3.7 times as much bone graft was applied to the debrideddisk space relative to disk material removed. This is explained by thefact that the disk space was collapsed at the time of diskectomy, andthen distracted and mobilized during the preparation process to adistracted height. This suggests that relying on an empiric 1:1 ratio ofdisk removal to BG insertion grossly under-fills the disk space andwould be an important contributor to pseudoarthrosis. This is anespecially important consideration in the most collapsed disk spacessince distraction to appropriate height in a non-collapsed disk reducesthe ratio to 8:12.3 (see FIG. 35A) or a 1:1.4 ratio.

The BG slurry used in this study consisted of a mixture of granularmaterial and liquid. This combination of materials does not behave as atypical, Newtonian (non-compressible) fluid. A non-Newtonian fluid willexude its fluid component as it is compressed, and the residual granularBG material occludes a conventional, cylindrical BG delivery device.

The BG delivery tool in this study revealed a number of advantages inthat it allowed for BG application in collapsed disc spaces due to itswedged tip, a process which is not possible with round-ended injectioncannulas. The increased cross sectional footprint relative to a roundcannula allowed considerably less friction of non-Newtonian fluidmaterial through the cannula, resulting in an increase in the BG flowdynamics, and eliminating jamming due to BG impaction. It is estimatedthat changing the cross-sectional area from 8 mm×8 mm to 8 mm×12 mmimproves the flow dynamics of a non-Newtonian fluid by 40%. The twosites for BG extrusion at the sides of the cannula tip double the exitzone surface area, further decreasing the resistance to flow of thegranular mixture. The removable funnel allowed direct visualization ofthe cannula as it was applied to the disk space without being obscuredby the funnel. The biportal expression of the BG material allowed graftinoculation of all prepared areas of the disk space and left a void forthe fusion cage. The applied BG delivery tool allowed refilling of thecannula without having to remove the device, resulting in decreasedpotential trauma to the adjacent nerve tissue.

The fusion rate in this study was 92.4% with three of thepseudoarthrosis patients having a diagnosis of hypothyroidism. This maybe related to abnormalities in bone metabolism associated in patientswith endocrinopathy. The other pseudoarthrosis patients did not haveapparent risk factors. Postoperative pain scores and functionalimprovement correlated with progression to arthrodesis.

In summary, preparation of the disk spaces at L4-S1 can deliver 34% ofthe disk volume during debridement. BG delivery was on average 3.7 timesthe volume of disk removal with a relatively higher ratio of BG beingdelivered to the more collapsed disk spaces. A novel BG delivery devicecan be used to dispense a volume of BG to the disk space that is capableof filling the entire debrided area in an efficient and safe fashion.This should allow for maximization of arthrodesis potential, increasepatient safety, and decrease operative time.

To provide further clarity to the Detailed Description provided hereinin the associated drawings, the following list of components andassociated numbering are provided as follows:

Reference No. Component 1 Integrated fusion cage and graft deliverydevice 2 Hollow tube 3 Hollow tube first exterior surface 4 Opening (ofHollow tube) 5 Hollow tube second exterior surface 6 First end (ofHollow tube) 7 Hollow tube first distal opening 8 Second end (of Hollowtube) 9 Hollow tube distal interior ramp 9A Hollow tube distal interiorramp surface 10 Curved surface (of Hollow tube) 10A Curved interiorsurface (of Hollow tube) 11 Footing (of Hollow tube) 12 Plunger 13Plunger distal first surface 14 Plunger distal second surface 15 Plungerdistal third surface 16 Handle (of Plunger) 17 Plunger medial portion 18Second end (of Plunger) 19 Horizontal surface (of Plunger) 20 Curvedsurface (of Plunger) 30 Funnel 32 Sleeve (of Funnel) 34 Opening (ofFunnel) 40 Disc space A Height of opening (in Hollow tube) B Width ofopening (in Hollow tube) 50 Wedge-shaped Second end (of Hollow tube) 52Wedge-shaped Second end (of Plunger) 60 Fusion Cage 62 Fusion Cage FirstEnd 64 Fusion Cage Second End 66 Fusion Cage First End Opening 68 FusionCage Medial Opening 69 Fusion Cage Lateral Opening 70 Fusion Cage MedialSurfaces 72 Fusion Cage Internal Ramps 80 Hollow Tube Locking Tabs 82Fusion Cage Locking Slots 90 Break-off Collar 100 Connector Conduit 102Connectors 110 ALIF Fusion Cage 112 ALIF Fusion Cage Portals 114 ALIFFusion Cage Chamber 116 ALIF Fusion Cage Break-off Collar 120 D-LIFFusion Cage 122 D-LIF Fusion Cage Portals 124 D-LIF Fusion Cage Chamber126 D-LIF Fusion Cage Break-off Collar 130 Vertebrectomy Fusion Cage 132Vertebrectomy Fusion Cage Porous Wall Portion 134 Vertebrectomy FusionCage Chamber 136 Vertebrectomy Fusion Cage Break-off Collar 138Vertebrectomy Fusion Cage Impervious Wall Portion

While various embodiment of the present disclosure have been describedin detail, it is apparent that modifications and alterations of thoseembodiments will occur to those skilled in the art. However, it is to beexpressly understood that such modifications and alterations are withinthe scope and spirit of the present disclosure, as set forth in thefollowing claims.

The foregoing discussion of the disclosure has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the disclosure to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of thedisclosure are grouped together in one or more embodiments for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimed disclosurerequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Thus, the followingclaims are hereby incorporated into this Detailed Description, with eachclaim standing on its own as a separate preferred embodiment of thedisclosure.

Moreover, though the present disclosure has included description of oneor more embodiments and certain variations and modifications, othervariations and modifications are within the scope of the disclosure,e.g., as may be within the skill and knowledge of those in the art,after understanding the present disclosure. It is intended to obtainrights which include alternative embodiments to the extent permitted,including alternate, interchangeable and/or equivalent structures,functions, ranges or steps to those claimed, whether or not suchalternate, interchangeable and/or equivalent structures, functions,ranges or steps are disclosed herein, and without intending to publiclydedicate any patentable subject matter.

What is claimed is:
 1. A bone graft insertion apparatus comprising: ahollow tube constructed to receive bone graft, said hollow tube havingan extended axis and a proximal end and a distal end, said hollow tubehaving a rectangular interior cross-section from said proximal end tosaid distal end, said distal end having a substantially tapered distaltip interior surface and a distal end interior surface of rectangularcross-section, said hollow tube of single-piece construction; a plungeradapted for inserting into said proximal end of said hollow tube, saidplunger having a distal end exterior surface of rectangularcross-section contoured to said distal end interior surface of saidhollow tube, said plunger of single-piece construction, said plungerdistal end exterior surface of rectangular cross-section forming asubstantially congruent fit with said hollow tube rectangular interiorcross-section, said plunger having a substantially tapered distal tipcontoured to said substantially tapered distal tip interior surface ofsaid hollow tube to form a substantially congruent fit, wherein saidhollow tube and said plunger are configured to deliver bone graftmaterial to a graft receiving area through one or more lateral openingsnear said distal end of said hollow tube, said plunger having an axiallength at least sufficient wherein at a least a portion of said plungerdistal end is positioned adjacent to said one or more lateral openingswhen fully inserted into said hollow tube, said one or more lateralopenings substantially precluding the delivery of bone graft materialdirectly along said axis of said hollow tube, said plunger precludedfrom rotating when inserted into said hollow tube.
 2. The apparatusaccording to claim 1, wherein said hollow tube comprises a ramp locatednear its distal end.
 3. The apparatus according to claim 1, wherein saiddistal end of said hollow tube has a curved surface located oppositesaid at least one opening.
 4. The apparatus according to claim 1,further comprising: a footing at said distal end of said hollow tube. 5.The apparatus according to claim 1, further comprising: a detachablefunnel connected to said proximal end of said hollow tube, wherein saiddetachable funnel facilitates insertion of said bone graft into saidhollow tube.
 6. The apparatus of claim 1, wherein said hollow tube has alength and said one or more lateral openings are solely located on alower half of said length.
 7. The apparatus of claim 1, wherein at leastone of said one or more lateral openings is at least one ofsubstantially oval and substantially rectangular.
 8. The apparatus ofclaim 1, wherein said distal end of at least one of said plunger andsaid hollow tube are constructed of material more flexible than materialcomprising said proximal end of said hollow tube.
 9. The apparatus ofclaim 1, wherein said hollow tube is preloaded with one of bone graftand bone morphogenic protein.
 10. The apparatus of claim 1, wherein saiddistal end of said hollow tube has at least one opening permitting bonegraft material to pass therethrough, said bone graft material passingthrough said opening along a path having an axis that is at an angle tosaid axis of said hollow tube, said angle between 2 degrees and 120degrees.
 11. The apparatus of claim 1, wherein said hollow tube has anangle at its distal end, said angle being between 5 degrees and 35degrees from the axis of the hollow tube.
 12. The apparatus of claim 1,wherein the hollow tube has at least one telescoping portion.
 13. A bonegraft insertion apparatus comprising: a hollow tube having a length, aproximal end and a distal end, said hollow tube having a rectangularinterior cross-section from said proximal end to said distal end, saiddistal end having a tapered tip interior surface and at least oneopening, said hollow tube of single-piece construction; a plungeradapted for insertion within said hollow tube at said proximal end ofsaid hollow tube, said plunger of single-piece construction, saidplunger having a distal end exterior surface of rectangularcross-section forming a substantially congruent fit with said hollowtube rectangular interior cross-section, said plunger having a distaltip contoured to conform to the distal end of said hollow tube, saidplunger having an axial length at least sufficient wherein at a least aportion of said plunger distal end is positioned adjacent to said one ormore lateral openings when fully inserted into said hollow tube, whereinsaid hollow tube and said plunger are configured to deliver bone graftmaterial to a graft receiving area through one or more lateral openingsnear said distal end of said hollow tube.
 14. The apparatus according toclaim 13, wherein said hollow tube has at least one ramp located nearits distal end.
 15. The apparatus according to claim 13, wherein atleast one opening is substantially oval.
 16. The apparatus according toclaim 13, wherein said at least opening is located on a lateral side ofsaid hollow tube.
 17. The apparatus according to claim 13, furthercomprising: a funnel located at said proximal end of said hollow tube.18. The apparatus of claim 13, wherein said hollow tube has a curvedsurface located opposite to said at least one opening.
 19. A bone graftinsertion apparatus comprising: a hollow tube constructed to receivebone graft having an extended axis, a length, a proximal end and adistal end, said hollow tube having a rectangular interior cross-sectionfrom said proximal end to said distal end, said distal end having atapered tip interior surface with a terminus and two oval-shapedopenings having an upper and a lower end located on opposite lateralsides of said distal end, said tapered tip extending into said hollowtube and said terminus positioned adjacent to said oval-shaped openings,said hollow tube of single-piece construction; a plunger adapted forinsertion within said hollow tube at said proximal end of said hollowtube, said plunger having a distal lower surface, said plunger ofsingle-piece construction, said plunger having a distal end exteriorsurface of rectangular cross-section forming a substantially congruentfit with said hollow tube rectangular interior cross-section, saidplunger having a length sufficient such that when fully inserted intosaid hollow tube, said plunger distal lower surface contacts said hollowtube terminus at a position adjacent to said oval-shaped openings, saidplunger rectangular cross-section end portion forming a continuoussurface adjacent each of the oval-shaped openings from a positionopposite said terminus to a point extending beyond said upper end ofeach oval-shaped opening; wherein said hollow tube and said plunger areconfigured to deliver bone graft material to a graft receiving areathrough said two oval-shaped openings near said distal end of saidhollow tube, said oval-shaped openings precluding the delivery of bonegraft material directly along said axis of said hollow tube, saidplunger precluded from rotating when inserted into said hollow tube;wherein said oval-shaped openings near the distal end of said hollowtube are positioned within a 25% length from said distal end relative toa total length of said hollow tube.